diff --git a/lib/content_management/bloc/create_headline/create_headline_bloc.dart b/lib/content_management/bloc/create_headline/create_headline_bloc.dart
index 7a053c5..5b491ee 100644
--- a/lib/content_management/bloc/create_headline/create_headline_bloc.dart
+++ b/lib/content_management/bloc/create_headline/create_headline_bloc.dart
@@ -1,4 +1,5 @@
 import 'package:bloc/bloc.dart';
+import 'package:bloc_concurrency/bloc_concurrency.dart';
 import 'package:core/core.dart';
 import 'package:data_repository/data_repository.dart';
 import 'package:equatable/equatable.dart';
@@ -8,6 +9,8 @@ import 'package:uuid/uuid.dart';
 part 'create_headline_event.dart';
 part 'create_headline_state.dart';
 
+const _searchDebounceDuration = Duration(milliseconds: 300);
+
 /// A BLoC to manage the state of creating a new headline.
 class CreateHeadlineBloc
     extends Bloc<CreateHeadlineEvent, CreateHeadlineState> {
@@ -32,6 +35,12 @@ class CreateHeadlineBloc
     on<CreateHeadlineCountryChanged>(_onCountryChanged);
     on<CreateHeadlineStatusChanged>(_onStatusChanged);
     on<CreateHeadlineSubmitted>(_onSubmitted);
+    on<CreateHeadlineCountrySearchChanged>(
+      _onCountrySearchChanged,
+      transformer: restartable(),
+    );
+    on<CreateHeadlineLoadMoreCountriesRequested>(
+        _onLoadMoreCountriesRequested);
   }
 
   final DataRepository<Headline> _headlinesRepository;
@@ -46,33 +55,30 @@ class CreateHeadlineBloc
   ) async {
     emit(state.copyWith(status: CreateHeadlineStatus.loading));
     try {
-      final [
-        sourcesResponse,
-        topicsResponse,
-        countriesResponse,
-      ] = await Future.wait([
+      final [sourcesResponse, topicsResponse] = await Future.wait([
         _sourcesRepository.readAll(
           sort: [const SortOption('updatedAt', SortOrder.desc)],
         ),
         _topicsRepository.readAll(
           sort: [const SortOption('updatedAt', SortOrder.desc)],
         ),
-        _countriesRepository.readAll(
-          sort: [const SortOption('name', SortOrder.asc)],
-        ),
       ]);
 
       final sources = (sourcesResponse as PaginatedResponse<Source>).items;
       final topics = (topicsResponse as PaginatedResponse<Topic>).items;
-      final countries =
-          (countriesResponse as PaginatedResponse<Country>).items;
+
+      final countriesResponse = await _countriesRepository.readAll(
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
 
       emit(
         state.copyWith(
           status: CreateHeadlineStatus.initial,
           sources: sources,
           topics: topics,
-          countries: countries,
+          countries: countriesResponse.items,
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
         ),
       );
     } on HttpException catch (e) {
@@ -189,4 +195,72 @@ class CreateHeadlineBloc
       );
     }
   }
+
+  Future<void> _onCountrySearchChanged(
+    CreateHeadlineCountrySearchChanged event,
+    Emitter<CreateHeadlineState> emit,
+  ) async {
+    await Future<void>.delayed(_searchDebounceDuration);
+    emit(state.copyWith(countrySearchTerm: event.searchTerm));
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        filter:
+            event.searchTerm.isNotEmpty ? {'name': event.searchTerm} : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: countriesResponse.items,
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: CreateHeadlineStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: CreateHeadlineStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLoadMoreCountriesRequested(
+    CreateHeadlineLoadMoreCountriesRequested event,
+    Emitter<CreateHeadlineState> emit,
+  ) async {
+    if (!state.countriesHasMore) return;
+
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        pagination: state.countriesCursor != null
+            ? PaginationOptions(cursor: state.countriesCursor)
+            : null,
+        filter: state.countrySearchTerm.isNotEmpty
+            ? {'name': state.countrySearchTerm}
+            : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: List.of(state.countries)..addAll(countriesResponse.items),
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: CreateHeadlineStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: CreateHeadlineStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
 }
diff --git a/lib/content_management/bloc/create_headline/create_headline_event.dart b/lib/content_management/bloc/create_headline/create_headline_event.dart
index 655eae9..b2dd90d 100644
--- a/lib/content_management/bloc/create_headline/create_headline_event.dart
+++ b/lib/content_management/bloc/create_headline/create_headline_event.dart
@@ -83,3 +83,17 @@ final class CreateHeadlineStatusChanged extends CreateHeadlineEvent {
 final class CreateHeadlineSubmitted extends CreateHeadlineEvent {
   const CreateHeadlineSubmitted();
 }
+
+/// Event for when the country search term is changed.
+final class CreateHeadlineCountrySearchChanged extends CreateHeadlineEvent {
+  const CreateHeadlineCountrySearchChanged(this.searchTerm);
+  final String searchTerm;
+  @override
+  List<Object?> get props => [searchTerm];
+}
+
+/// Event to request loading more countries.
+final class CreateHeadlineLoadMoreCountriesRequested
+    extends CreateHeadlineEvent {
+  const CreateHeadlineLoadMoreCountriesRequested();
+}
diff --git a/lib/content_management/bloc/create_headline/create_headline_state.dart b/lib/content_management/bloc/create_headline/create_headline_state.dart
index 0739db1..c914953 100644
--- a/lib/content_management/bloc/create_headline/create_headline_state.dart
+++ b/lib/content_management/bloc/create_headline/create_headline_state.dart
@@ -32,6 +32,9 @@ final class CreateHeadlineState extends Equatable {
     this.sources = const [],
     this.topics = const [],
     this.countries = const [],
+    this.countriesHasMore = true,
+    this.countriesCursor,
+    this.countrySearchTerm = '',
     this.contentStatus = ContentStatus.active,
     this.exception,
     this.createdHeadline,
@@ -48,6 +51,9 @@ final class CreateHeadlineState extends Equatable {
   final List<Source> sources;
   final List<Topic> topics;
   final List<Country> countries;
+  final bool countriesHasMore;
+  final String? countriesCursor;
+  final String countrySearchTerm;
   final ContentStatus contentStatus;
   final HttpException? exception;
   final Headline? createdHeadline;
@@ -74,6 +80,9 @@ final class CreateHeadlineState extends Equatable {
     List<Source>? sources,
     List<Topic>? topics,
     List<Country>? countries,
+    bool? countriesHasMore,
+    String? countriesCursor,
+    String? countrySearchTerm,
     ContentStatus? contentStatus,
     HttpException? exception,
     Headline? createdHeadline,
@@ -90,6 +99,9 @@ final class CreateHeadlineState extends Equatable {
       sources: sources ?? this.sources,
       topics: topics ?? this.topics,
       countries: countries ?? this.countries,
+      countriesHasMore: countriesHasMore ?? this.countriesHasMore,
+      countriesCursor: countriesCursor ?? this.countriesCursor,
+      countrySearchTerm: countrySearchTerm ?? this.countrySearchTerm,
       contentStatus: contentStatus ?? this.contentStatus,
       exception: exception,
       createdHeadline: createdHeadline ?? this.createdHeadline,
@@ -109,6 +121,9 @@ final class CreateHeadlineState extends Equatable {
     sources,
     topics,
     countries,
+    countriesHasMore,
+    countriesCursor,
+    countrySearchTerm,
     contentStatus,
     exception,
     createdHeadline,
diff --git a/lib/content_management/bloc/create_source/create_source_bloc.dart b/lib/content_management/bloc/create_source/create_source_bloc.dart
index 312f505..fe4e63b 100644
--- a/lib/content_management/bloc/create_source/create_source_bloc.dart
+++ b/lib/content_management/bloc/create_source/create_source_bloc.dart
@@ -1,4 +1,5 @@
 import 'package:bloc/bloc.dart';
+import 'package:bloc_concurrency/bloc_concurrency.dart';
 import 'package:core/core.dart';
 import 'package:data_repository/data_repository.dart';
 import 'package:equatable/equatable.dart';
@@ -8,6 +9,8 @@ import 'package:uuid/uuid.dart';
 part 'create_source_event.dart';
 part 'create_source_state.dart';
 
+const _searchDebounceDuration = Duration(milliseconds: 300);
+
 /// A BLoC to manage the state of creating a new source.
 class CreateSourceBloc extends Bloc<CreateSourceEvent, CreateSourceState> {
   /// {@macro create_source_bloc}
@@ -28,6 +31,20 @@ class CreateSourceBloc extends Bloc<CreateSourceEvent, CreateSourceState> {
     on<CreateSourceHeadquartersChanged>(_onHeadquartersChanged);
     on<CreateSourceStatusChanged>(_onStatusChanged);
     on<CreateSourceSubmitted>(_onSubmitted);
+    on<CreateSourceCountrySearchChanged>(
+      _onCountrySearchChanged,
+      transformer: restartable(),
+    );
+    on<CreateSourceLoadMoreCountriesRequested>(
+      _onLoadMoreCountriesRequested,
+    );
+    on<CreateSourceLanguageSearchChanged>(
+      _onLanguageSearchChanged,
+      transformer: restartable(),
+    );
+    on<CreateSourceLoadMoreLanguagesRequested>(
+      _onLoadMoreLanguagesRequested,
+    );
   }
 
   final DataRepository<Source> _sourcesRepository;
@@ -41,7 +58,7 @@ class CreateSourceBloc extends Bloc<CreateSourceEvent, CreateSourceState> {
   ) async {
     emit(state.copyWith(status: CreateSourceStatus.loading));
     try {
-      final [countriesResponse, languagesResponse] = await Future.wait([
+      final responses = await Future.wait([
         _countriesRepository.readAll(
           sort: [const SortOption('name', SortOrder.asc)],
         ),
@@ -49,19 +66,28 @@ class CreateSourceBloc extends Bloc<CreateSourceEvent, CreateSourceState> {
           sort: [const SortOption('name', SortOrder.asc)],
         ),
       ]);
-
-      final countries = (countriesResponse as PaginatedResponse<Country>).items;
-      final languages = (languagesResponse as PaginatedResponse<Language>).items;
-
+      final countriesPaginated = responses[0] as PaginatedResponse<Country>;
+      final languagesPaginated = responses[1] as PaginatedResponse<Language>;
       emit(
         state.copyWith(
           status: CreateSourceStatus.initial,
-          countries: countries,
-          languages: languages,
+          countries: countriesPaginated.items,
+          countriesCursor: countriesPaginated.cursor,
+          countriesHasMore: countriesPaginated.hasMore,
+          languages: languagesPaginated.items,
+          languagesCursor: languagesPaginated.cursor,
+          languagesHasMore: languagesPaginated.hasMore,
         ),
       );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: CreateSourceStatus.failure, exception: e));
     } catch (e) {
-      emit(state.copyWith(status: CreateSourceStatus.failure));
+      emit(
+        state.copyWith(
+          status: CreateSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
     }
   }
 
@@ -159,4 +185,141 @@ class CreateSourceBloc extends Bloc<CreateSourceEvent, CreateSourceState> {
       );
     }
   }
+
+  Future<void> _onCountrySearchChanged(
+    CreateSourceCountrySearchChanged event,
+    Emitter<CreateSourceState> emit,
+  ) async {
+    await Future<void>.delayed(_searchDebounceDuration);
+    emit(state.copyWith(countrySearchTerm: event.searchTerm));
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        filter:
+            event.searchTerm.isNotEmpty ? {'name': event.searchTerm} : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: countriesResponse.items,
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: CreateSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: CreateSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLoadMoreCountriesRequested(
+    CreateSourceLoadMoreCountriesRequested event,
+    Emitter<CreateSourceState> emit,
+  ) async {
+    if (!state.countriesHasMore) return;
+
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        pagination: state.countriesCursor != null
+            ? PaginationOptions(cursor: state.countriesCursor)
+            : null,
+        filter: state.countrySearchTerm.isNotEmpty
+            ? {'name': state.countrySearchTerm}
+            : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: List.of(state.countries)..addAll(countriesResponse.items),
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: CreateSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: CreateSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLanguageSearchChanged(
+    CreateSourceLanguageSearchChanged event,
+    Emitter<CreateSourceState> emit,
+  ) async {
+    await Future<void>.delayed(_searchDebounceDuration);
+    emit(state.copyWith(languageSearchTerm: event.searchTerm));
+    try {
+      final languagesResponse = await _languagesRepository.readAll(
+        filter:
+            event.searchTerm.isNotEmpty ? {'name': event.searchTerm} : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          languages: languagesResponse.items,
+          languagesCursor: languagesResponse.cursor,
+          languagesHasMore: languagesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: CreateSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: CreateSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLoadMoreLanguagesRequested(
+    CreateSourceLoadMoreLanguagesRequested event,
+    Emitter<CreateSourceState> emit,
+  ) async {
+    if (!state.languagesHasMore) return;
+
+    try {
+      final languagesResponse = await _languagesRepository.readAll(
+        pagination: state.languagesCursor != null
+            ? PaginationOptions(cursor: state.languagesCursor)
+            : null,
+        filter: state.languageSearchTerm.isNotEmpty
+            ? {'name': state.languageSearchTerm}
+            : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          languages: List.of(state.languages)
+            ..addAll(languagesResponse.items),
+          languagesCursor: languagesResponse.cursor,
+          languagesHasMore: languagesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: CreateSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: CreateSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
 }
diff --git a/lib/content_management/bloc/create_source/create_source_event.dart b/lib/content_management/bloc/create_source/create_source_event.dart
index e4c4f56..d15f2f4 100644
--- a/lib/content_management/bloc/create_source/create_source_event.dart
+++ b/lib/content_management/bloc/create_source/create_source_event.dart
@@ -75,3 +75,29 @@ final class CreateSourceStatusChanged extends CreateSourceEvent {
 final class CreateSourceSubmitted extends CreateSourceEvent {
   const CreateSourceSubmitted();
 }
+
+/// Event for when the country search term is changed.
+final class CreateSourceCountrySearchChanged extends CreateSourceEvent {
+  const CreateSourceCountrySearchChanged(this.searchTerm);
+  final String searchTerm;
+  @override
+  List<Object?> get props => [searchTerm];
+}
+
+/// Event to request loading more countries.
+final class CreateSourceLoadMoreCountriesRequested extends CreateSourceEvent {
+  const CreateSourceLoadMoreCountriesRequested();
+}
+
+/// Event for when the language search term is changed.
+final class CreateSourceLanguageSearchChanged extends CreateSourceEvent {
+  const CreateSourceLanguageSearchChanged(this.searchTerm);
+  final String searchTerm;
+  @override
+  List<Object?> get props => [searchTerm];
+}
+
+/// Event to request loading more languages.
+final class CreateSourceLoadMoreLanguagesRequested extends CreateSourceEvent {
+  const CreateSourceLoadMoreLanguagesRequested();
+}
diff --git a/lib/content_management/bloc/create_source/create_source_state.dart b/lib/content_management/bloc/create_source/create_source_state.dart
index d86c2c5..783a200 100644
--- a/lib/content_management/bloc/create_source/create_source_state.dart
+++ b/lib/content_management/bloc/create_source/create_source_state.dart
@@ -30,7 +30,13 @@ final class CreateSourceState extends Equatable {
     this.language,
     this.headquarters,
     this.countries = const [],
+    this.countriesHasMore = true,
+    this.countriesCursor,
+    this.countrySearchTerm = '',
     this.languages = const [],
+    this.languagesHasMore = true,
+    this.languagesCursor,
+    this.languageSearchTerm = '',
     this.contentStatus = ContentStatus.active,
     this.exception,
     this.createdSource,
@@ -44,7 +50,13 @@ final class CreateSourceState extends Equatable {
   final Language? language;
   final Country? headquarters;
   final List<Country> countries;
+  final bool countriesHasMore;
+  final String? countriesCursor;
+  final String countrySearchTerm;
   final List<Language> languages;
+  final bool languagesHasMore;
+  final String? languagesCursor;
+  final String languageSearchTerm;
   final ContentStatus contentStatus;
   final HttpException? exception;
   final Source? createdSource;
@@ -67,7 +79,13 @@ final class CreateSourceState extends Equatable {
     ValueGetter<Language?>? language,
     ValueGetter<Country?>? headquarters,
     List<Country>? countries,
+    bool? countriesHasMore,
+    String? countriesCursor,
+    String? countrySearchTerm,
     List<Language>? languages,
+    bool? languagesHasMore,
+    String? languagesCursor,
+    String? languageSearchTerm,
     ContentStatus? contentStatus,
     HttpException? exception,
     Source? createdSource,
@@ -81,7 +99,13 @@ final class CreateSourceState extends Equatable {
       language: language != null ? language() : this.language,
       headquarters: headquarters != null ? headquarters() : this.headquarters,
       countries: countries ?? this.countries,
+      countriesHasMore: countriesHasMore ?? this.countriesHasMore,
+      countriesCursor: countriesCursor ?? this.countriesCursor,
+      countrySearchTerm: countrySearchTerm ?? this.countrySearchTerm,
       languages: languages ?? this.languages,
+      languagesHasMore: languagesHasMore ?? this.languagesHasMore,
+      languagesCursor: languagesCursor ?? this.languagesCursor,
+      languageSearchTerm: languageSearchTerm ?? this.languageSearchTerm,
       contentStatus: contentStatus ?? this.contentStatus,
       exception: exception,
       createdSource: createdSource ?? this.createdSource,
@@ -97,8 +121,14 @@ final class CreateSourceState extends Equatable {
     sourceType,
     language,
     headquarters,
-        countries,
-        languages,
+    countries,
+    countriesHasMore,
+    countriesCursor,
+    countrySearchTerm,
+    languages,
+    languagesHasMore,
+    languagesCursor,
+    languageSearchTerm,
     contentStatus,
     exception,
     createdSource,
diff --git a/lib/content_management/bloc/edit_headline/edit_headline_bloc.dart b/lib/content_management/bloc/edit_headline/edit_headline_bloc.dart
index 02a64f4..412cde1 100644
--- a/lib/content_management/bloc/edit_headline/edit_headline_bloc.dart
+++ b/lib/content_management/bloc/edit_headline/edit_headline_bloc.dart
@@ -1,4 +1,5 @@
 import 'package:bloc/bloc.dart';
+import 'package:bloc_concurrency/bloc_concurrency.dart';
 import 'package:core/core.dart';
 import 'package:data_repository/data_repository.dart';
 import 'package:equatable/equatable.dart';
@@ -7,6 +8,8 @@ import 'package:flutter/foundation.dart';
 part 'edit_headline_event.dart';
 part 'edit_headline_state.dart';
 
+const _searchDebounceDuration = Duration(milliseconds: 300);
+
 /// A BLoC to manage the state of editing a single headline.
 class EditHeadlineBloc extends Bloc<EditHeadlineEvent, EditHeadlineState> {
   /// {@macro edit_headline_bloc}
@@ -32,6 +35,13 @@ class EditHeadlineBloc extends Bloc<EditHeadlineEvent, EditHeadlineState> {
     on<EditHeadlineCountryChanged>(_onCountryChanged);
     on<EditHeadlineStatusChanged>(_onStatusChanged);
     on<EditHeadlineSubmitted>(_onSubmitted);
+    on<EditHeadlineCountrySearchChanged>(
+      _onCountrySearchChanged,
+      transformer: restartable(),
+    );
+    on<EditHeadlineLoadMoreCountriesRequested>(
+      _onLoadMoreCountriesRequested,
+    );
   }
 
   final DataRepository<Headline> _headlinesRepository;
@@ -46,12 +56,7 @@ class EditHeadlineBloc extends Bloc<EditHeadlineEvent, EditHeadlineState> {
   ) async {
     emit(state.copyWith(status: EditHeadlineStatus.loading));
     try {
-      final [
-        headlineResponse,
-        sourcesResponse,
-        topicsResponse,
-        countriesResponse,
-      ] = await Future.wait([
+      final responses = await Future.wait([
         _headlinesRepository.read(id: _headlineId),
         _sourcesRepository.readAll(
           sort: [const SortOption('updatedAt', SortOrder.desc)],
@@ -59,15 +64,15 @@ class EditHeadlineBloc extends Bloc<EditHeadlineEvent, EditHeadlineState> {
         _topicsRepository.readAll(
           sort: [const SortOption('updatedAt', SortOrder.desc)],
         ),
-        _countriesRepository.readAll(
-          sort: [const SortOption('name', SortOrder.asc)],
-        ),
       ]);
 
-      final headline = headlineResponse as Headline;
-      final sources = (sourcesResponse as PaginatedResponse<Source>).items;
-      final topics = (topicsResponse as PaginatedResponse<Topic>).items;
-      final countries = (countriesResponse as PaginatedResponse<Country>).items;
+      final headline = responses[0] as Headline;
+      final sources = (responses[1] as PaginatedResponse<Source>).items;
+      final topics = (responses[2] as PaginatedResponse<Topic>).items;
+
+      final countriesResponse = await _countriesRepository.readAll(
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
 
       emit(
         state.copyWith(
@@ -82,7 +87,9 @@ class EditHeadlineBloc extends Bloc<EditHeadlineEvent, EditHeadlineState> {
           eventCountry: () => headline.eventCountry,
           sources: sources,
           topics: topics,
-          countries: countries,
+          countries: countriesResponse.items,
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
           contentStatus: headline.status,
         ),
       );
@@ -237,4 +244,72 @@ class EditHeadlineBloc extends Bloc<EditHeadlineEvent, EditHeadlineState> {
       );
     }
   }
+
+  Future<void> _onCountrySearchChanged(
+    EditHeadlineCountrySearchChanged event,
+    Emitter<EditHeadlineState> emit,
+  ) async {
+    await Future<void>.delayed(_searchDebounceDuration);
+    emit(state.copyWith(countrySearchTerm: event.searchTerm));
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        filter:
+            event.searchTerm.isNotEmpty ? {'name': event.searchTerm} : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: countriesResponse.items,
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: EditHeadlineStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: EditHeadlineStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLoadMoreCountriesRequested(
+    EditHeadlineLoadMoreCountriesRequested event,
+    Emitter<EditHeadlineState> emit,
+  ) async {
+    if (!state.countriesHasMore) return;
+
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        pagination: state.countriesCursor != null
+            ? PaginationOptions(cursor: state.countriesCursor)
+            : null,
+        filter: state.countrySearchTerm.isNotEmpty
+            ? {'name': state.countrySearchTerm}
+            : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: List.of(state.countries)..addAll(countriesResponse.items),
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: EditHeadlineStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: EditHeadlineStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
 }
diff --git a/lib/content_management/bloc/edit_headline/edit_headline_event.dart b/lib/content_management/bloc/edit_headline/edit_headline_event.dart
index 6bad7bd..f07256d 100644
--- a/lib/content_management/bloc/edit_headline/edit_headline_event.dart
+++ b/lib/content_management/bloc/edit_headline/edit_headline_event.dart
@@ -83,3 +83,16 @@ final class EditHeadlineStatusChanged extends EditHeadlineEvent {
 final class EditHeadlineSubmitted extends EditHeadlineEvent {
   const EditHeadlineSubmitted();
 }
+
+/// Event for when the country search term is changed.
+final class EditHeadlineCountrySearchChanged extends EditHeadlineEvent {
+  const EditHeadlineCountrySearchChanged(this.searchTerm);
+  final String searchTerm;
+  @override
+  List<Object?> get props => [searchTerm];
+}
+
+/// Event to request loading more countries.
+final class EditHeadlineLoadMoreCountriesRequested extends EditHeadlineEvent {
+  const EditHeadlineLoadMoreCountriesRequested();
+}
diff --git a/lib/content_management/bloc/edit_headline/edit_headline_state.dart b/lib/content_management/bloc/edit_headline/edit_headline_state.dart
index fba983f..11e5b07 100644
--- a/lib/content_management/bloc/edit_headline/edit_headline_state.dart
+++ b/lib/content_management/bloc/edit_headline/edit_headline_state.dart
@@ -33,6 +33,9 @@ final class EditHeadlineState extends Equatable {
     this.sources = const [],
     this.topics = const [],
     this.countries = const [],
+    this.countriesHasMore = true,
+    this.countriesCursor,
+    this.countrySearchTerm = '',
     this.contentStatus = ContentStatus.active,
     this.exception,
     this.updatedHeadline,
@@ -50,6 +53,9 @@ final class EditHeadlineState extends Equatable {
   final List<Source> sources;
   final List<Topic> topics;
   final List<Country> countries;
+  final bool countriesHasMore;
+  final String? countriesCursor;
+  final String countrySearchTerm;
   final ContentStatus contentStatus;
   final HttpException? exception;
   final Headline? updatedHeadline;
@@ -77,6 +83,9 @@ final class EditHeadlineState extends Equatable {
     List<Source>? sources,
     List<Topic>? topics,
     List<Country>? countries,
+    bool? countriesHasMore,
+    String? countriesCursor,
+    String? countrySearchTerm,
     ContentStatus? contentStatus,
     HttpException? exception,
     Headline? updatedHeadline,
@@ -94,6 +103,9 @@ final class EditHeadlineState extends Equatable {
       sources: sources ?? this.sources,
       topics: topics ?? this.topics,
       countries: countries ?? this.countries,
+      countriesHasMore: countriesHasMore ?? this.countriesHasMore,
+      countriesCursor: countriesCursor ?? this.countriesCursor,
+      countrySearchTerm: countrySearchTerm ?? this.countrySearchTerm,
       contentStatus: contentStatus ?? this.contentStatus,
       exception: exception,
       updatedHeadline: updatedHeadline ?? this.updatedHeadline,
@@ -114,6 +126,9 @@ final class EditHeadlineState extends Equatable {
     sources,
     topics,
     countries,
+    countriesHasMore,
+    countriesCursor,
+    countrySearchTerm,
     contentStatus,
     exception,
     updatedHeadline,
diff --git a/lib/content_management/bloc/edit_source/edit_source_bloc.dart b/lib/content_management/bloc/edit_source/edit_source_bloc.dart
index fb652af..c8d8c7a 100644
--- a/lib/content_management/bloc/edit_source/edit_source_bloc.dart
+++ b/lib/content_management/bloc/edit_source/edit_source_bloc.dart
@@ -1,4 +1,5 @@
 import 'package:bloc/bloc.dart';
+import 'package:bloc_concurrency/bloc_concurrency.dart';
 import 'package:core/core.dart';
 import 'package:data_repository/data_repository.dart';
 import 'package:equatable/equatable.dart';
@@ -7,6 +8,8 @@ import 'package:flutter/foundation.dart';
 part 'edit_source_event.dart';
 part 'edit_source_state.dart';
 
+const _searchDebounceDuration = Duration(milliseconds: 300);
+
 /// A BLoC to manage the state of editing a single source.
 class EditSourceBloc extends Bloc<EditSourceEvent, EditSourceState> {
   /// {@macro edit_source_bloc}
@@ -29,6 +32,20 @@ class EditSourceBloc extends Bloc<EditSourceEvent, EditSourceState> {
     on<EditSourceHeadquartersChanged>(_onHeadquartersChanged);
     on<EditSourceStatusChanged>(_onStatusChanged);
     on<EditSourceSubmitted>(_onSubmitted);
+    on<EditSourceCountrySearchChanged>(
+      _onCountrySearchChanged,
+      transformer: restartable(),
+    );
+    on<EditSourceLoadMoreCountriesRequested>(
+      _onLoadMoreCountriesRequested,
+    );
+    on<EditSourceLanguageSearchChanged>(
+      _onLanguageSearchChanged,
+      transformer: restartable(),
+    );
+    on<EditSourceLoadMoreLanguagesRequested>(
+      _onLoadMoreLanguagesRequested,
+    );
   }
 
   final DataRepository<Source> _sourcesRepository;
@@ -42,11 +59,7 @@ class EditSourceBloc extends Bloc<EditSourceEvent, EditSourceState> {
   ) async {
     emit(state.copyWith(status: EditSourceStatus.loading));
     try {
-      final [
-        sourceResponse,
-        countriesResponse,
-        languagesResponse,
-      ] = await Future.wait([
+      final responses = await Future.wait<dynamic>([
         _sourcesRepository.read(id: _sourceId),
         _countriesRepository.readAll(
           sort: [const SortOption('name', SortOrder.asc)],
@@ -56,17 +69,20 @@ class EditSourceBloc extends Bloc<EditSourceEvent, EditSourceState> {
         ),
       ]);
 
-      final source = sourceResponse as Source;
-      final countries = (countriesResponse as PaginatedResponse<Country>).items;
-      final languages = (languagesResponse as PaginatedResponse<Language>).items;
+      final source = responses[0] as Source;
+      final countriesPaginated = responses[1] as PaginatedResponse<Country>;
+      final languagesPaginated = responses[2] as PaginatedResponse<Language>;
 
-      // The source contains a Language object. We need to find the equivalent
-      // object in the full list of languages to ensure the DropdownButton
-      // can correctly identify and display the initial selection by reference.
-      final selectedLanguage = languages.firstWhere(
-        (listLanguage) => listLanguage == source.language,
-        orElse: () => source.language,
-      );
+      Language? selectedLanguage;
+      try {
+        // Find the equivalent language object from the full list.
+        // This ensures the DropdownButton can identify it by reference.
+        selectedLanguage = languagesPaginated.items.firstWhere(
+          (listLanguage) => listLanguage.id == source.language?.id,
+        );
+      } catch (_) {
+        selectedLanguage = source.language;
+      }
 
       emit(
         state.copyWith(
@@ -79,8 +95,12 @@ class EditSourceBloc extends Bloc<EditSourceEvent, EditSourceState> {
           language: () => selectedLanguage,
           headquarters: () => source.headquarters,
           contentStatus: source.status,
-          countries: countries,
-          languages: languages,
+          countries: countriesPaginated.items,
+          countriesCursor: countriesPaginated.cursor,
+          countriesHasMore: countriesPaginated.hasMore,
+          languages: languagesPaginated.items,
+          languagesCursor: languagesPaginated.cursor,
+          languagesHasMore: languagesPaginated.hasMore,
         ),
       );
     } on HttpException catch (e) {
@@ -219,4 +239,140 @@ class EditSourceBloc extends Bloc<EditSourceEvent, EditSourceState> {
       );
     }
   }
+
+  Future<void> _onCountrySearchChanged(
+    EditSourceCountrySearchChanged event,
+    Emitter<EditSourceState> emit,
+  ) async {
+    await Future<void>.delayed(_searchDebounceDuration);
+    emit(state.copyWith(countrySearchTerm: event.searchTerm));
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        filter:
+            event.searchTerm.isNotEmpty ? {'name': event.searchTerm} : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: countriesResponse.items,
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: EditSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: EditSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLoadMoreCountriesRequested(
+    EditSourceLoadMoreCountriesRequested event,
+    Emitter<EditSourceState> emit,
+  ) async {
+    if (!state.countriesHasMore) return;
+
+    try {
+      final countriesResponse = await _countriesRepository.readAll(
+        pagination: state.countriesCursor != null
+            ? PaginationOptions(cursor: state.countriesCursor)
+            : null,
+        filter: state.countrySearchTerm.isNotEmpty
+            ? {'name': state.countrySearchTerm}
+            : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          countries: List.of(state.countries)..addAll(countriesResponse.items),
+          countriesCursor: countriesResponse.cursor,
+          countriesHasMore: countriesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: EditSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: EditSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLanguageSearchChanged(
+    EditSourceLanguageSearchChanged event,
+    Emitter<EditSourceState> emit,
+  ) async {
+    await Future<void>.delayed(_searchDebounceDuration);
+    emit(state.copyWith(languageSearchTerm: event.searchTerm));
+    try {
+      final languagesResponse = await _languagesRepository.readAll(
+        filter:
+            event.searchTerm.isNotEmpty ? {'name': event.searchTerm} : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          languages: languagesResponse.items,
+          languagesCursor: languagesResponse.cursor,
+          languagesHasMore: languagesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: EditSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: EditSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
+
+  Future<void> _onLoadMoreLanguagesRequested(
+    EditSourceLoadMoreLanguagesRequested event,
+    Emitter<EditSourceState> emit,
+  ) async {
+    if (!state.languagesHasMore) return;
+
+    try {
+      final languagesResponse = await _languagesRepository.readAll(
+        pagination: state.languagesCursor != null
+            ? PaginationOptions(cursor: state.languagesCursor)
+            : null,
+        filter: state.languageSearchTerm.isNotEmpty
+            ? {'name': state.languageSearchTerm}
+            : null,
+        sort: [const SortOption('name', SortOrder.asc)],
+      );
+
+      emit(
+        state.copyWith(
+          languages: List.of(state.languages)..addAll(languagesResponse.items),
+          languagesCursor: languagesResponse.cursor,
+          languagesHasMore: languagesResponse.hasMore,
+        ),
+      );
+    } on HttpException catch (e) {
+      emit(state.copyWith(status: EditSourceStatus.failure, exception: e));
+    } catch (e) {
+      emit(
+        state.copyWith(
+          status: EditSourceStatus.failure,
+          exception: UnknownException('An unexpected error occurred: $e'),
+        ),
+      );
+    }
+  }
 }
diff --git a/lib/content_management/bloc/edit_source/edit_source_event.dart b/lib/content_management/bloc/edit_source/edit_source_event.dart
index 8620d9a..b68ec43 100644
--- a/lib/content_management/bloc/edit_source/edit_source_event.dart
+++ b/lib/content_management/bloc/edit_source/edit_source_event.dart
@@ -86,3 +86,29 @@ final class EditSourceStatusChanged extends EditSourceEvent {
 final class EditSourceSubmitted extends EditSourceEvent {
   const EditSourceSubmitted();
 }
+
+/// Event for when the country search term is changed.
+final class EditSourceCountrySearchChanged extends EditSourceEvent {
+  const EditSourceCountrySearchChanged(this.searchTerm);
+  final String searchTerm;
+  @override
+  List<Object?> get props => [searchTerm];
+}
+
+/// Event to request loading more countries.
+final class EditSourceLoadMoreCountriesRequested extends EditSourceEvent {
+  const EditSourceLoadMoreCountriesRequested();
+}
+
+/// Event for when the language search term is changed.
+final class EditSourceLanguageSearchChanged extends EditSourceEvent {
+  const EditSourceLanguageSearchChanged(this.searchTerm);
+  final String searchTerm;
+  @override
+  List<Object?> get props => [searchTerm];
+}
+
+/// Event to request loading more languages.
+final class EditSourceLoadMoreLanguagesRequested extends EditSourceEvent {
+  const EditSourceLoadMoreLanguagesRequested();
+}
diff --git a/lib/content_management/bloc/edit_source/edit_source_state.dart b/lib/content_management/bloc/edit_source/edit_source_state.dart
index 1c65c6a..f4e3281 100644
--- a/lib/content_management/bloc/edit_source/edit_source_state.dart
+++ b/lib/content_management/bloc/edit_source/edit_source_state.dart
@@ -30,7 +30,13 @@ final class EditSourceState extends Equatable {
     this.language,
     this.headquarters,
     this.countries = const [],
+    this.countriesHasMore = true,
+    this.countriesCursor,
+    this.countrySearchTerm = '',
     this.languages = const [],
+    this.languagesHasMore = true,
+    this.languagesCursor,
+    this.languageSearchTerm = '',
     this.contentStatus = ContentStatus.active,
     this.exception,
     this.updatedSource,
@@ -45,7 +51,13 @@ final class EditSourceState extends Equatable {
   final Language? language;
   final Country? headquarters;
   final List<Country> countries;
+  final bool countriesHasMore;
+  final String? countriesCursor;
+  final String countrySearchTerm;
   final List<Language> languages;
+  final bool languagesHasMore;
+  final String? languagesCursor;
+  final String languageSearchTerm;
   final ContentStatus contentStatus;
   final HttpException? exception;
   final Source? updatedSource;
@@ -69,7 +81,13 @@ final class EditSourceState extends Equatable {
     ValueGetter<Language?>? language,
     ValueGetter<Country?>? headquarters,
     List<Country>? countries,
+    bool? countriesHasMore,
+    String? countriesCursor,
+    String? countrySearchTerm,
     List<Language>? languages,
+    bool? languagesHasMore,
+    String? languagesCursor,
+    String? languageSearchTerm,
     ContentStatus? contentStatus,
     HttpException? exception,
     Source? updatedSource,
@@ -84,7 +102,13 @@ final class EditSourceState extends Equatable {
       language: language != null ? language() : this.language,
       headquarters: headquarters != null ? headquarters() : this.headquarters,
       countries: countries ?? this.countries,
+      countriesHasMore: countriesHasMore ?? this.countriesHasMore,
+      countriesCursor: countriesCursor ?? this.countriesCursor,
+      countrySearchTerm: countrySearchTerm ?? this.countrySearchTerm,
       languages: languages ?? this.languages,
+      languagesHasMore: languagesHasMore ?? this.languagesHasMore,
+      languagesCursor: languagesCursor ?? this.languagesCursor,
+      languageSearchTerm: languageSearchTerm ?? this.languageSearchTerm,
       contentStatus: contentStatus ?? this.contentStatus,
       exception: exception,
       updatedSource: updatedSource ?? this.updatedSource,
@@ -102,7 +126,13 @@ final class EditSourceState extends Equatable {
     language,
     headquarters,
     countries,
+    countriesHasMore,
+    countriesCursor,
+    countrySearchTerm,
     languages,
+    languagesHasMore,
+    languagesCursor,
+    languageSearchTerm,
     contentStatus,
     exception,
     updatedSource,
diff --git a/lib/content_management/view/create_headline_page.dart b/lib/content_management/view/create_headline_page.dart
index 204da4e..8311014 100644
--- a/lib/content_management/view/create_headline_page.dart
+++ b/lib/content_management/view/create_headline_page.dart
@@ -214,13 +214,54 @@ class _CreateHeadlineViewState extends State<_CreateHeadlineView> {
                           .add(CreateHeadlineTopicChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
-                    CountryDropdownFormField(
+                    SearchableDropdownFormField<Country>(
                       labelText: l10n.countryName,
-                      countries: state.countries,
+                      items: state.countries,
                       initialValue: state.eventCountry,
+                      hasMore: state.countriesHasMore,
+                      isLoading: state.status == CreateHeadlineStatus.loading,
                       onChanged: (value) => context
                           .read<CreateHeadlineBloc>()
                           .add(CreateHeadlineCountryChanged(value)),
+                      onSearchChanged: (value) => context
+                          .read<CreateHeadlineBloc>()
+                          .add(CreateHeadlineCountrySearchChanged(value)),
+                      onLoadMore: () => context.read<CreateHeadlineBloc>().add(
+                            const CreateHeadlineLoadMoreCountriesRequested(),
+                          ),
+                      itemBuilder: (context, country) {
+                        return ListTile(
+                          leading: SizedBox(
+                            width: 32,
+                            height: 20,
+                            child: Image.network(
+                              country.flagUrl,
+                              fit: BoxFit.cover,
+                              errorBuilder: (context, error, stackTrace) =>
+                                  const Icon(Icons.flag),
+                            ),
+                          ),
+                          title: Text(country.name),
+                        );
+                      },
+                      selectedItemBuilder: (context, country) {
+                        return Row(
+                          children: [
+                            SizedBox(
+                              width: 32,
+                              height: 20,
+                              child: Image.network(
+                                country.flagUrl,
+                                fit: BoxFit.cover,
+                                errorBuilder: (context, error, stackTrace) =>
+                                    const Icon(Icons.flag),
+                              ),
+                            ),
+                            const SizedBox(width: AppSpacing.md),
+                            Text(country.name),
+                          ],
+                        );
+                      },
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<ContentStatus>(
diff --git a/lib/content_management/view/create_source_page.dart b/lib/content_management/view/create_source_page.dart
index 2de3892..a623b2b 100644
--- a/lib/content_management/view/create_source_page.dart
+++ b/lib/content_management/view/create_source_page.dart
@@ -161,13 +161,29 @@ class _CreateSourceViewState extends State<_CreateSourceView> {
                           .add(CreateSourceUrlChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
-                    LanguageDropdownFormField(
+                    SearchableDropdownFormField<Language>(
                       labelText: l10n.language,
-                      languages: state.languages,
+                      items: state.languages,
                       initialValue: state.language,
+                      hasMore: state.languagesHasMore,
+                      isLoading: state.status == CreateSourceStatus.loading,
                       onChanged: (value) => context
                           .read<CreateSourceBloc>()
                           .add(CreateSourceLanguageChanged(value)),
+                      onSearchChanged: (value) => context
+                          .read<CreateSourceBloc>()
+                          .add(CreateSourceLanguageSearchChanged(value)),
+                      onLoadMore: () => context.read<CreateSourceBloc>().add(
+                            const CreateSourceLoadMoreLanguagesRequested(),
+                          ),
+                      itemBuilder: (context, language) {
+                        return ListTile(
+                          title: Text(language.name),
+                        );
+                      },
+                      selectedItemBuilder: (context, language) {
+                        return Text(language.name);
+                      },
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<SourceType?>(
@@ -190,13 +206,54 @@ class _CreateSourceViewState extends State<_CreateSourceView> {
                           .add(CreateSourceTypeChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
-                    CountryDropdownFormField(
+                    SearchableDropdownFormField<Country>(
                       labelText: l10n.headquarters,
-                      countries: state.countries,
+                      items: state.countries,
                       initialValue: state.headquarters,
+                      hasMore: state.countriesHasMore,
+                      isLoading: state.status == CreateSourceStatus.loading,
                       onChanged: (value) => context
                           .read<CreateSourceBloc>()
                           .add(CreateSourceHeadquartersChanged(value)),
+                      onSearchChanged: (value) => context
+                          .read<CreateSourceBloc>()
+                          .add(CreateSourceCountrySearchChanged(value)),
+                      onLoadMore: () => context.read<CreateSourceBloc>().add(
+                            const CreateSourceLoadMoreCountriesRequested(),
+                          ),
+                      itemBuilder: (context, country) {
+                        return ListTile(
+                          leading: SizedBox(
+                            width: 32,
+                            height: 20,
+                            child: Image.network(
+                              country.flagUrl,
+                              fit: BoxFit.cover,
+                              errorBuilder: (context, error, stackTrace) =>
+                                  const Icon(Icons.flag),
+                            ),
+                          ),
+                          title: Text(country.name),
+                        );
+                      },
+                      selectedItemBuilder: (context, country) {
+                        return Row(
+                          children: [
+                            SizedBox(
+                              width: 32,
+                              height: 20,
+                              child: Image.network(
+                                country.flagUrl,
+                                fit: BoxFit.cover,
+                                errorBuilder: (context, error, stackTrace) =>
+                                    const Icon(Icons.flag),
+                              ),
+                            ),
+                            const SizedBox(width: AppSpacing.md),
+                            Text(country.name),
+                          ],
+                        );
+                      },
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<ContentStatus>(
diff --git a/lib/content_management/view/edit_headline_page.dart b/lib/content_management/view/edit_headline_page.dart
index 9387a25..2b9cc85 100644
--- a/lib/content_management/view/edit_headline_page.dart
+++ b/lib/content_management/view/edit_headline_page.dart
@@ -282,13 +282,54 @@ class _EditHeadlineViewState extends State<_EditHeadlineView> {
                           .add(EditHeadlineTopicChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
-                    CountryDropdownFormField(
+                    SearchableDropdownFormField<Country>(
                       labelText: l10n.countryName,
-                      countries: state.countries,
+                      items: state.countries,
                       initialValue: selectedCountry,
+                      hasMore: state.countriesHasMore,
+                      isLoading: state.status == EditHeadlineStatus.loading,
                       onChanged: (value) => context
                           .read<EditHeadlineBloc>()
                           .add(EditHeadlineCountryChanged(value)),
+                      onSearchChanged: (value) => context
+                          .read<EditHeadlineBloc>()
+                          .add(EditHeadlineCountrySearchChanged(value)),
+                      onLoadMore: () => context.read<EditHeadlineBloc>().add(
+                            const EditHeadlineLoadMoreCountriesRequested(),
+                          ),
+                      itemBuilder: (context, country) {
+                        return ListTile(
+                          leading: SizedBox(
+                            width: 32,
+                            height: 20,
+                            child: Image.network(
+                              country.flagUrl,
+                              fit: BoxFit.cover,
+                              errorBuilder: (context, error, stackTrace) =>
+                                  const Icon(Icons.flag),
+                            ),
+                          ),
+                          title: Text(country.name),
+                        );
+                      },
+                      selectedItemBuilder: (context, country) {
+                        return Row(
+                          children: [
+                            SizedBox(
+                              width: 32,
+                              height: 20,
+                              child: Image.network(
+                                country.flagUrl,
+                                fit: BoxFit.cover,
+                                errorBuilder: (context, error, stackTrace) =>
+                                    const Icon(Icons.flag),
+                              ),
+                            ),
+                            const SizedBox(width: AppSpacing.md),
+                            Text(country.name),
+                          ],
+                        );
+                      },
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<ContentStatus>(
diff --git a/lib/content_management/view/edit_source_page.dart b/lib/content_management/view/edit_source_page.dart
index b532b81..bbdb844 100644
--- a/lib/content_management/view/edit_source_page.dart
+++ b/lib/content_management/view/edit_source_page.dart
@@ -191,13 +191,29 @@ class _EditSourceViewState extends State<_EditSourceView> {
                       ),
                     ),
                     const SizedBox(height: AppSpacing.lg),
-                    LanguageDropdownFormField(
+                    SearchableDropdownFormField<Language>(
                       labelText: l10n.language,
-                      languages: state.languages,
+                      items: state.languages,
                       initialValue: state.language,
+                      hasMore: state.languagesHasMore,
+                      isLoading: state.status == EditSourceStatus.loading,
                       onChanged: (value) => context
                           .read<EditSourceBloc>()
                           .add(EditSourceLanguageChanged(value)),
+                      onSearchChanged: (value) => context
+                          .read<EditSourceBloc>()
+                          .add(EditSourceLanguageSearchChanged(value)),
+                      onLoadMore: () => context.read<EditSourceBloc>().add(
+                            const EditSourceLoadMoreLanguagesRequested(),
+                          ),
+                      itemBuilder: (context, language) {
+                        return ListTile(
+                          title: Text(language.name),
+                        );
+                      },
+                      selectedItemBuilder: (context, language) {
+                        return Text(language.name);
+                      },
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<SourceType?>(
@@ -220,13 +236,54 @@ class _EditSourceViewState extends State<_EditSourceView> {
                       ),
                     ),
                     const SizedBox(height: AppSpacing.lg),
-                    CountryDropdownFormField(
+                    SearchableDropdownFormField<Country>(
                       labelText: l10n.headquarters,
-                      countries: state.countries,
+                      items: state.countries,
                       initialValue: state.headquarters,
+                      hasMore: state.countriesHasMore,
+                      isLoading: state.status == EditSourceStatus.loading,
                       onChanged: (value) => context
                           .read<EditSourceBloc>()
                           .add(EditSourceHeadquartersChanged(value)),
+                      onSearchChanged: (value) => context
+                          .read<EditSourceBloc>()
+                          .add(EditSourceCountrySearchChanged(value)),
+                      onLoadMore: () => context.read<EditSourceBloc>().add(
+                            const EditSourceLoadMoreCountriesRequested(),
+                          ),
+                      itemBuilder: (context, country) {
+                        return ListTile(
+                          leading: SizedBox(
+                            width: 32,
+                            height: 20,
+                            child: Image.network(
+                              country.flagUrl,
+                              fit: BoxFit.cover,
+                              errorBuilder: (context, error, stackTrace) =>
+                                  const Icon(Icons.flag),
+                            ),
+                          ),
+                          title: Text(country.name),
+                        );
+                      },
+                      selectedItemBuilder: (context, country) {
+                        return Row(
+                          children: [
+                            SizedBox(
+                              width: 32,
+                              height: 20,
+                              child: Image.network(
+                                country.flagUrl,
+                                fit: BoxFit.cover,
+                                errorBuilder: (context, error, stackTrace) =>
+                                    const Icon(Icons.flag),
+                              ),
+                            ),
+                            const SizedBox(width: AppSpacing.md),
+                            Text(country.name),
+                          ],
+                        );
+                      },
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<ContentStatus>(
diff --git a/lib/shared/widgets/country_dropdown_form_field.dart b/lib/shared/widgets/country_dropdown_form_field.dart
deleted file mode 100644
index edcb47d..0000000
--- a/lib/shared/widgets/country_dropdown_form_field.dart
+++ /dev/null
@@ -1,47 +0,0 @@
-import 'package:core/core.dart';
-import 'package:flutter/material.dart';
-import 'package:flutter_news_app_web_dashboard_full_source_code/l10n/l10n.dart';
-
-/// A reusable dropdown form field for selecting a country.
-class CountryDropdownFormField extends StatelessWidget {
-  /// {@macro country_dropdown_form_field}
-  const CountryDropdownFormField({
-    required this.countries,
-    required this.onChanged,
-    this.initialValue,
-    this.labelText,
-    super.key,
-  });
-
-  /// The list of countries to display in the dropdown.
-  final List<Country> countries;
-
-  /// The currently selected country.
-  final Country? initialValue;
-
-  /// The callback that is called when the user selects a country.
-  final ValueChanged<Country?> onChanged;
-
-  /// The text to display as the label for the form field.
-  final String? labelText;
-
-  @override
-  Widget build(BuildContext context) {
-    final l10n = AppLocalizationsX(context).l10n;
-
-    return DropdownButtonFormField<Country?>(
-      value: initialValue,
-      decoration: InputDecoration(
-        labelText: labelText ?? l10n.countryName,
-        border: const OutlineInputBorder(),
-      ),
-      items: [
-        DropdownMenuItem(value: null, child: Text(l10n.none)),
-        ...countries.map(
-          (c) => DropdownMenuItem(value: c, child: Text(c.name)),
-        ),
-      ],
-      onChanged: onChanged,
-    );
-  }
-}
diff --git a/lib/shared/widgets/language_dropdown_form_field.dart b/lib/shared/widgets/language_dropdown_form_field.dart
deleted file mode 100644
index dc8e1d4..0000000
--- a/lib/shared/widgets/language_dropdown_form_field.dart
+++ /dev/null
@@ -1,47 +0,0 @@
-import 'package:core/core.dart';
-import 'package:flutter/material.dart';
-import 'package:flutter_news_app_web_dashboard_full_source_code/l10n/l10n.dart';
-
-/// A reusable dropdown form field for selecting a language.
-class LanguageDropdownFormField extends StatelessWidget {
-  /// {@macro language_dropdown_form_field}
-  const LanguageDropdownFormField({
-    required this.languages,
-    required this.onChanged,
-    this.initialValue,
-    this.labelText,
-    super.key,
-  });
-
-  /// The list of languages to display in the dropdown.
-  final List<Language> languages;
-
-  /// The currently selected language.
-  final Language? initialValue;
-
-  /// The callback that is called when the user selects a language.
-  final ValueChanged<Language?> onChanged;
-
-  /// The text to display as the label for the form field.
-  final String? labelText;
-
-  @override
-  Widget build(BuildContext context) {
-    final l10n = AppLocalizationsX(context).l10n;
-
-    return DropdownButtonFormField<Language?>(
-      value: initialValue,
-      decoration: InputDecoration(
-        labelText: labelText ?? l10n.language,
-        border: const OutlineInputBorder(),
-      ),
-      items: [
-        DropdownMenuItem(value: null, child: Text(l10n.none)),
-        ...languages.map(
-          (l) => DropdownMenuItem(value: l, child: Text(l.name)),
-        ),
-      ],
-      onChanged: onChanged,
-    );
-  }
-}
diff --git a/lib/shared/widgets/searchable_dropdown_form_field.dart b/lib/shared/widgets/searchable_dropdown_form_field.dart
new file mode 100644
index 0000000..d5887ee
--- /dev/null
+++ b/lib/shared/widgets/searchable_dropdown_form_field.dart
@@ -0,0 +1,210 @@
+import 'package:flutter/material.dart';
+import 'package:ui_kit/ui_kit.dart';
+
+/// A generic type for the builder function that creates list items in the
+/// searchable dropdown.
+typedef SearchableDropdownItemBuilder<T> = Widget Function(
+  BuildContext context,
+  T item,
+);
+
+/// A generic type for the builder function that creates the widget to display
+/// the selected item within the form field.
+typedef SearchableDropdownSelectedItemBuilder<T> = Widget Function(
+  BuildContext context,
+  T item,
+);
+
+/// A form field that allows users to select an item from a searchable,
+/// paginated list displayed in a modal dialog.
+///
+/// This widget is generic and can be used for any type [T]. It requires
+/// builders for constructing the list items and the selected item display,
+/// as well as callbacks to handle searching and pagination.
+class SearchableDropdownFormField<T> extends FormField<T> {
+  /// {@macro searchable_dropdown_form_field}
+  SearchableDropdownFormField({
+    required List<T> items,
+    required ValueChanged<T?> onChanged,
+    required ValueChanged<String> onSearchChanged,
+    required VoidCallback onLoadMore,
+    required SearchableDropdownItemBuilder<T> itemBuilder,
+    required SearchableDropdownSelectedItemBuilder<T> selectedItemBuilder,
+    required bool hasMore,
+    bool? isLoading,
+    super.key,
+    T? initialValue,
+    String? labelText,
+    String? searchHintText,
+    String? noItemsFoundText,
+    super.onSaved,
+    super.validator,
+    super.autovalidateMode = AutovalidateMode.onUserInteraction,
+  }) : super(
+          initialValue: initialValue,
+          builder: (FormFieldState<T> state) {
+            // This is the widget that will be displayed in the form.
+            // It looks like a text field but opens a dialog on tap.
+            return InkWell(
+              onTap: () async {
+                final selectedItem = await showDialog<T>(
+                  context: state.context,
+                  builder: (context) => _SearchableSelectionDialog<T>(
+                    items: items,
+                    onSearchChanged: onSearchChanged,
+                    onLoadMore: onLoadMore,
+                    itemBuilder: itemBuilder,
+                    hasMore: hasMore,
+                    isLoading: isLoading ?? false,
+                    searchHintText: searchHintText,
+                    noItemsFoundText: noItemsFoundText,
+                  ),
+                );
+
+                if (selectedItem != null) {
+                  state.didChange(selectedItem);
+                  onChanged(selectedItem);
+                }
+              },
+              child: InputDecorator(
+                decoration: InputDecoration(
+                  labelText: labelText,
+                  border: const OutlineInputBorder(),
+                  errorText: state.errorText,
+                  suffixIcon: const Icon(Icons.arrow_drop_down),
+                ),
+                child: state.value == null
+                    ? const SizedBox(height: 20) // To maintain field height
+                    : selectedItemBuilder(state.context, state.value as T),
+              ),
+            );
+          },
+        );
+}
+
+/// The modal dialog that contains the searchable and paginated list.
+class _SearchableSelectionDialog<T> extends StatefulWidget {
+  const _SearchableSelectionDialog({
+    required this.items,
+    required this.onSearchChanged,
+    required this.onLoadMore,
+    required this.itemBuilder,
+    required this.hasMore,
+    required this.isLoading,
+    this.searchHintText,
+    this.noItemsFoundText,
+    super.key,
+  });
+
+  final List<T> items;
+  final ValueChanged<String> onSearchChanged;
+  final VoidCallback onLoadMore;
+  final SearchableDropdownItemBuilder<T> itemBuilder;
+  final bool hasMore;
+  final bool isLoading;
+  final String? searchHintText;
+  final String? noItemsFoundText;
+
+  @override
+  State<_SearchableSelectionDialog<T>> createState() =>
+      _SearchableSelectionDialogState<T>();
+}
+
+class _SearchableSelectionDialogState<T>
+    extends State<_SearchableSelectionDialog<T>> {
+  final _scrollController = ScrollController();
+  final _searchController = TextEditingController();
+
+  @override
+  void initState() {
+    super.initState();
+    _scrollController.addListener(_onScroll);
+    _searchController.addListener(() {
+      widget.onSearchChanged(_searchController.text);
+    });
+  }
+
+  @override
+  void dispose() {
+    _scrollController
+      ..removeListener(_onScroll)
+      ..dispose();
+    _searchController.dispose();
+    super.dispose();
+  }
+
+  void _onScroll() {
+    if (_isBottom) {
+      widget.onLoadMore();
+    }
+  }
+
+  bool get _isBottom {
+    if (!_scrollController.hasClients) return false;
+    final maxScroll = _scrollController.position.maxScrollExtent;
+    final currentScroll = _scrollController.offset;
+    // Add a small buffer to trigger before reaching the absolute bottom.
+    return currentScroll >= (maxScroll * 0.9);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Dialog(
+      child: SizedBox(
+        width: 400,
+        height: 600,
+        child: Padding(
+          padding: const EdgeInsets.all(AppSpacing.lg),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              TextField(
+                controller: _searchController,
+                decoration: InputDecoration(
+                  hintText: widget.searchHintText ?? 'Search...',
+                  prefixIcon: const Icon(Icons.search),
+                  border: const OutlineInputBorder(),
+                ),
+              ),
+              const SizedBox(height: AppSpacing.md),
+              Expanded(
+                child: _buildList(),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget _buildList() {
+    if (widget.isLoading && widget.items.isEmpty) {
+      return const Center(child: CircularProgressIndicator());
+    }
+
+    if (widget.items.isEmpty) {
+      return Center(
+        child: Text(widget.noItemsFoundText ?? 'No items found.'),
+      );
+    }
+
+    return ListView.builder(
+      controller: _scrollController,
+      itemCount:
+          widget.hasMore ? widget.items.length + 1 : widget.items.length,
+      itemBuilder: (context, index) {
+        if (index >= widget.items.length) {
+          return const Padding(
+            padding: EdgeInsets.symmetric(vertical: AppSpacing.md),
+            child: Center(child: CircularProgressIndicator()),
+          );
+        }
+        final item = widget.items[index];
+        return InkWell(
+          onTap: () => Navigator.of(context).pop(item),
+          child: widget.itemBuilder(context, item),
+        );
+      },
+    );
+  }
+}
\ No newline at end of file
diff --git a/lib/shared/widgets/widgets.dart b/lib/shared/widgets/widgets.dart
index c108713..70d878e 100644
--- a/lib/shared/widgets/widgets.dart
+++ b/lib/shared/widgets/widgets.dart
@@ -1,2 +1 @@
-export 'country_dropdown_form_field.dart';
-export 'language_dropdown_form_field.dart';
+export 'searchable_dropdown_form_field.dart';