diff --git a/goldens/material/datepicker/index.api.md b/goldens/material/datepicker/index.api.md
index 8f109cabded8..f7d1db2fb8ff 100644
--- a/goldens/material/datepicker/index.api.md
+++ b/goldens/material/datepicker/index.api.md
@@ -109,7 +109,7 @@ export class MatCalendar<D> implements AfterContentInit, AfterViewChecked, OnDes
     get currentView(): MatCalendarView;
     set currentView(value: MatCalendarView);
     dateClass: MatCalendarCellClassFunction<D>;
-    dateFilter: (date: D) => boolean;
+    dateFilter?: ((date: D) => boolean) | null;
     _dateSelected(event: MatCalendarUserEvent<D | null>): void;
     _dragEnded(event: MatCalendarUserEvent<DateRange<D> | null>): void;
     _dragStarted(event: MatCalendarUserEvent<D>): void;
@@ -373,7 +373,7 @@ export class MatDatepickerContent<S, D = ExtractDateTypeFromSelection<S>> implem
 // @public
 export interface MatDatepickerControl<D> {
     // (undocumented)
-    dateFilter: DateFilterFn<D>;
+    dateFilter: DateFilterFn<D> | null | undefined;
     // (undocumented)
     disabled: boolean;
     // (undocumented)
@@ -398,12 +398,12 @@ export class MatDatepickerInput<D> extends MatDatepickerInputBase<D | null, D> i
     protected _ariaOwns: i0.WritableSignal<string | null>;
     // (undocumented)
     protected _assignValueToModel(value: D | null): void;
-    get dateFilter(): DateFilterFn<D | null>;
-    set dateFilter(value: DateFilterFn<D | null>);
+    get dateFilter(): DateFilterFn<D | null> | null | undefined;
+    set dateFilter(value: DateFilterFn<D | null> | null | undefined);
     // (undocumented)
     _datepicker: MatDatepickerPanel<MatDatepickerControl<D>, D | null, D>;
     getConnectedOverlayOrigin(): ElementRef;
-    protected _getDateFilter(): DateFilterFn<D | null>;
+    protected _getDateFilter(): DateFilterFn<D | null> | null | undefined;
     _getMaxDate(): D | null;
     _getMinDate(): D | null;
     getOverlayLabelId(): string | null;
@@ -534,8 +534,8 @@ export class MatDateRangeInput<D> implements MatFormFieldControl<DateRange<D>>,
     comparisonEnd: D | null;
     comparisonStart: D | null;
     controlType: string;
-    get dateFilter(): DateFilterFn<D>;
-    set dateFilter(value: DateFilterFn<D>);
+    get dateFilter(): DateFilterFn<D> | null | undefined;
+    set dateFilter(value: DateFilterFn<D> | null | undefined);
     get describedByIds(): string[];
     readonly disableAutomaticLabeling = true;
     get disabled(): boolean;
@@ -673,7 +673,7 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
     // (undocumented)
     _dateAdapter: DateAdapter<D, any>;
     dateClass: MatCalendarCellClassFunction<D>;
-    dateFilter: (date: D) => boolean;
+    dateFilter: ((date: D) => boolean) | null | undefined;
     _dateSelected(event: MatCalendarUserEvent<number>): void;
     readonly dragEnded: EventEmitter<MatCalendarUserEvent<DateRange<D> | null>>;
     protected _dragEnded(event: MatCalendarUserEvent<D | null>): void;
@@ -731,7 +731,7 @@ export class MatMultiYearView<D> implements AfterContentInit, OnDestroy {
     // (undocumented)
     _dateAdapter: DateAdapter<D, any>;
     dateClass: MatCalendarCellClassFunction<D>;
-    dateFilter: (date: D) => boolean;
+    dateFilter: ((date: D) => boolean) | null | undefined;
     _focusActiveCell(): void;
     _focusActiveCellAfterViewChecked(): void;
     // (undocumented)
@@ -820,7 +820,7 @@ export class MatYearView<D> implements AfterContentInit, OnDestroy {
     // (undocumented)
     _dateAdapter: DateAdapter<D, any>;
     dateClass: MatCalendarCellClassFunction<D>;
-    dateFilter: (date: D) => boolean;
+    dateFilter: ((date: D) => boolean) | null | undefined;
     _focusActiveCell(): void;
     _focusActiveCellAfterViewChecked(): void;
     _handleCalendarBodyKeydown(event: KeyboardEvent): void;
diff --git a/src/material/datepicker/calendar.ts b/src/material/datepicker/calendar.ts
index 9f54fb28a703..436070604eae 100644
--- a/src/material/datepicker/calendar.ts
+++ b/src/material/datepicker/calendar.ts
@@ -327,7 +327,7 @@ export class MatCalendar<D> implements AfterContentInit, AfterViewChecked, OnDes
   private _maxDate: D | null;
 
   /** Function used to filter which dates are selectable. */
-  @Input() dateFilter: (date: D) => boolean;
+  @Input() dateFilter?: ((date: D) => boolean) | null;
 
   /** Function that can be used to add custom CSS classes to dates. */
   @Input() dateClass: MatCalendarCellClassFunction<D>;
diff --git a/src/material/datepicker/date-range-input.ts b/src/material/datepicker/date-range-input.ts
index 0d507fd3c24a..86992cb617c4 100644
--- a/src/material/datepicker/date-range-input.ts
+++ b/src/material/datepicker/date-range-input.ts
@@ -154,7 +154,7 @@ export class MatDateRangeInput<D>
   get dateFilter() {
     return this._dateFilter;
   }
-  set dateFilter(value: DateFilterFn<D>) {
+  set dateFilter(value: DateFilterFn<D> | null | undefined) {
     const start = this._startInput;
     const end = this._endInput;
     const wasMatchingStart = start && start._matchesFilter(start.value);
@@ -169,7 +169,7 @@ export class MatDateRangeInput<D>
       end._validatorOnChange();
     }
   }
-  private _dateFilter: DateFilterFn<D>;
+  private _dateFilter?: DateFilterFn<D> | null;
 
   /** The minimum valid date. */
   @Input()
diff --git a/src/material/datepicker/datepicker-base.ts b/src/material/datepicker/datepicker-base.ts
index e8cef6970bfc..657923acc31e 100644
--- a/src/material/datepicker/datepicker-base.ts
+++ b/src/material/datepicker/datepicker-base.ts
@@ -325,7 +325,7 @@ export interface MatDatepickerControl<D> {
   min: D | null;
   max: D | null;
   disabled: boolean;
-  dateFilter: DateFilterFn<D>;
+  dateFilter: DateFilterFn<D> | null | undefined;
   getConnectedOverlayOrigin(): ElementRef;
   getOverlayLabelId(): string | null;
   stateChanges: Observable<void>;
@@ -524,7 +524,7 @@ export abstract class MatDatepickerBase<
     return this.datepickerInput && this.datepickerInput.max;
   }
 
-  _getDateFilter(): DateFilterFn<D> {
+  _getDateFilter(): DateFilterFn<D> | null | undefined {
     return this.datepickerInput && this.datepickerInput.dateFilter;
   }
 
diff --git a/src/material/datepicker/datepicker-input-base.ts b/src/material/datepicker/datepicker-input-base.ts
index 632cec9d45a4..01de0feb77b5 100644
--- a/src/material/datepicker/datepicker-input-base.ts
+++ b/src/material/datepicker/datepicker-input-base.ts
@@ -203,7 +203,7 @@ export abstract class MatDatepickerInputBase<S, D = ExtractDateTypeFromSelection
   abstract _getMaxDate(): D | null;
 
   /** Gets the date filter function. Used for validation. */
-  protected abstract _getDateFilter(): DateFilterFn<D> | undefined;
+  protected abstract _getDateFilter(): DateFilterFn<D> | null | undefined;
 
   /** Registers a date selection model with the input. */
   _registerModel(model: MatDateSelectionModel<S, D>): void {
diff --git a/src/material/datepicker/datepicker-input.ts b/src/material/datepicker/datepicker-input.ts
index d555a1b5812e..dea01bd24252 100644
--- a/src/material/datepicker/datepicker-input.ts
+++ b/src/material/datepicker/datepicker-input.ts
@@ -119,7 +119,7 @@ export class MatDatepickerInput<D>
   get dateFilter() {
     return this._dateFilter;
   }
-  set dateFilter(value: DateFilterFn<D | null>) {
+  set dateFilter(value: DateFilterFn<D | null> | null | undefined) {
     const wasMatchingValue = this._matchesFilter(this.value);
     this._dateFilter = value;
 
@@ -127,7 +127,7 @@ export class MatDatepickerInput<D>
       this._validatorOnChange();
     }
   }
-  private _dateFilter: DateFilterFn<D | null>;
+  private _dateFilter: DateFilterFn<D | null> | null | undefined;
 
   /** The combined form control validator for this input. */
   protected _validator: ValidatorFn | null;
diff --git a/src/material/datepicker/month-view.ts b/src/material/datepicker/month-view.ts
index ff8a43696121..6631c3b3360b 100644
--- a/src/material/datepicker/month-view.ts
+++ b/src/material/datepicker/month-view.ts
@@ -141,7 +141,7 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
   private _maxDate: D | null;
 
   /** Function used to filter which dates are selectable. */
-  @Input() dateFilter: (date: D) => boolean;
+  @Input() dateFilter: ((date: D) => boolean) | null | undefined;
 
   /** Function that can be used to add custom CSS classes to dates. */
   @Input() dateClass: MatCalendarCellClassFunction<D>;
diff --git a/src/material/datepicker/multi-year-view.ts b/src/material/datepicker/multi-year-view.ts
index dc832f9e4f5e..6fd4c88b89a3 100644
--- a/src/material/datepicker/multi-year-view.ts
+++ b/src/material/datepicker/multi-year-view.ts
@@ -133,7 +133,7 @@ export class MatMultiYearView<D> implements AfterContentInit, OnDestroy {
   private _maxDate: D | null;
 
   /** A function used to filter which dates are selectable. */
-  @Input() dateFilter: (date: D) => boolean;
+  @Input() dateFilter: ((date: D) => boolean) | null | undefined;
 
   /** Function that can be used to add custom CSS classes to date cells. */
   @Input() dateClass: MatCalendarCellClassFunction<D>;
diff --git a/src/material/datepicker/year-view.ts b/src/material/datepicker/year-view.ts
index 97af5be58020..89482b0b67b7 100644
--- a/src/material/datepicker/year-view.ts
+++ b/src/material/datepicker/year-view.ts
@@ -122,7 +122,7 @@ export class MatYearView<D> implements AfterContentInit, OnDestroy {
   private _maxDate: D | null;
 
   /** A function used to filter which dates are selectable. */
-  @Input() dateFilter: (date: D) => boolean;
+  @Input() dateFilter: ((date: D) => boolean) | null | undefined;
 
   /** Function that can be used to add custom CSS classes to date cells. */
   @Input() dateClass: MatCalendarCellClassFunction<D>;