diff --git a/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/DataSourceService.java b/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/DataSourceService.java
index 34dfb9db..9eceb0ff 100644
--- a/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/DataSourceService.java
+++ b/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/DataSourceService.java
@@ -181,7 +181,7 @@ public void moveMany(List<Integer> ids, int targetFolderId) {
     public void hardDeleteOne(int dataSourceId) {
         DataSource ds = dataSourceRepository.findById(dataSourceId)
                 .orElseThrow(() -> new NoResultException("존재하지 않는 자료입니다."));
-        deleteOwnedImageIfAny(ds);
+//        deleteOwnedImageIfAny(ds);
         dataSourceRepository.delete(ds);
     }
 
@@ -190,7 +190,7 @@ public void hardDeleteMany(List<Integer> ids) {
         if (ids == null || ids.isEmpty()) return;
         List<DataSource> list = dataSourceRepository.findAllById(ids);
         if (list.size() != ids.size()) throw new NoResultException("존재하지 않는 자료 포함");
-        for (DataSource ds : list) deleteOwnedImageIfAny(ds);
+//        for (DataSource ds : list) deleteOwnedImageIfAny(ds);
         dataSourceRepository.deleteAll(list);
     }
 
@@ -321,19 +321,15 @@ public String uploadThumbnailAndReturnFinalUrl(MultipartFile image, String key)
 
     // ===== S3 삭제 관련 유틸 =====
     // 소유한 이미지가 있으면 S3에서 삭제
-    private void deleteOwnedImageIfAny(DataSource ds) {
-        String url = ds.getImageUrl();
-        if (url == null || url.isBlank()) return;
-        if (!isOurS3Url(url)) return;
-
-        String key = extractKeyFromUrl(url);
-        if (key == null || key.isBlank()) return;
-
-        try {
-            s3Service.delete(key);
-        } catch (Exception ignore) {
-            // 파일 삭제 실패로 전체 삭제를 롤백하지 않음
-            // 필요하면 warn 로그 추가
+    public void deleteIfOwnedByExactKey(String imageUrl, String expectedKey) {
+        if (imageUrl == null || imageUrl.isBlank() || expectedKey == null || expectedKey.isBlank()) return;
+        String key = extractKeyFromUrl(imageUrl);
+        if (expectedKey.equals(key)) {
+            try {
+                s3Service.delete(key);
+            } catch (Exception ignore) {
+                // S3 삭제 실패가 전체 트랜잭션을 막지 않도록 무시
+            }
         }
     }
 
diff --git a/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/PersonalDataSourceService.java b/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/PersonalDataSourceService.java
index e711257a..1e9c126a 100644
--- a/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/PersonalDataSourceService.java
+++ b/src/main/java/org/tuna/zoopzoop/backend/domain/datasource/service/PersonalDataSourceService.java
@@ -16,6 +16,7 @@
 import org.tuna.zoopzoop.backend.domain.datasource.dto.DataSourceSearchCondition;
 import org.tuna.zoopzoop.backend.domain.datasource.dto.DataSourceSearchItem;
 import org.tuna.zoopzoop.backend.domain.datasource.dto.UpdateOutcome;
+import org.tuna.zoopzoop.backend.domain.datasource.entity.DataSource;
 import org.tuna.zoopzoop.backend.domain.datasource.entity.Tag;
 import org.tuna.zoopzoop.backend.domain.datasource.repository.DataSourceRepository;
 
@@ -79,9 +80,13 @@ public int create(int memberId, String sourceUrl, Integer folderIdOrZero, DataSo
     // hard delete
     @Transactional
     public int deleteOne(int memberId, int dataSourceId) {
-        dataSourceRepository.findByIdAndMemberId(dataSourceId, memberId)
+        DataSource ds = dataSourceRepository.findByIdAndMemberId(dataSourceId, memberId)
                 .orElseThrow(() -> new NoResultException("존재하지 않는 자료입니다."));
 
+        // S3 삭제
+        String expectedKey = domain.thumbnailKeyForPersonal(memberId, dataSourceId);
+        domain.deleteIfOwnedByExactKey(ds.getImageUrl(), expectedKey);
+
         domain.hardDeleteOne(dataSourceId);
         return dataSourceId;
     }
@@ -98,6 +103,13 @@ public void deleteMany(int memberId, List<Integer> ids) {
             missing.removeAll(new HashSet<>(existing));
             throw new NoResultException("존재하지 않거나 소유자가 다른 자료 ID 포함: " + missing);
         }
+        // S3 삭제
+        List<DataSource> list = dataSourceRepository.findAllById(ids);
+        for (DataSource ds : list) {
+            String expectedKey = domain.thumbnailKeyForPersonal(memberId, ds.getId());
+            domain.deleteIfOwnedByExactKey(ds.getImageUrl(), expectedKey);
+        }
+
         domain.hardDeleteMany(ids);
     }