diff --git a/packages/flutter/lib/src/material/dropdown_menu.dart b/packages/flutter/lib/src/material/dropdown_menu.dart
index 8ae003a424..97e89fd40b 100644
--- a/packages/flutter/lib/src/material/dropdown_menu.dart
+++ b/packages/flutter/lib/src/material/dropdown_menu.dart
@@ -830,6 +830,7 @@ class _DropdownMenuState<T> extends State<DropdownMenu<T>> {
           focusNode: widget.focusNode,
           canRequestFocus: canRequestFocus(),
           enableInteractiveSelection: canRequestFocus(),
+          readOnly: !canRequestFocus(),
           keyboardType: widget.keyboardType,
           textAlign: widget.textAlign,
           textAlignVertical: TextAlignVertical.center,
diff --git a/packages/flutter/test/material/dropdown_menu_test.dart b/packages/flutter/test/material/dropdown_menu_test.dart
index 98b04eefa0..c285513e3a 100644
--- a/packages/flutter/test/material/dropdown_menu_test.dart
+++ b/packages/flutter/test/material/dropdown_menu_test.dart
@@ -2442,6 +2442,7 @@ void main() {
       MaterialApp(
         home: Scaffold(
           body: DropdownMenu<String>(
+            requestFocusOnTap: true,
             controller: controller,
             dropdownMenuEntries: const <DropdownMenuEntry<String>>[
               DropdownMenuEntry<String>(
@@ -2675,6 +2676,53 @@ void main() {
       expect(find.widgetWithText(MenuItemButton, menu.label), findsNWidgets(2));
     }
   });
+
+  // This is a regression test for https://github.com/flutter/flutter/issues/151686.
+  testWidgets('Setting DropdownMenu.requestFocusOnTap to false makes TextField read only', (WidgetTester tester) async {
+    const String label = 'Test';
+    Widget buildDropdownMenu({ bool? requestFocusOnTap }) {
+      return MaterialApp(
+        home: Scaffold(
+          body: Center(
+            child: DropdownMenu<TestMenu>(
+              requestFocusOnTap: requestFocusOnTap,
+              dropdownMenuEntries: menuChildren,
+              hintText: label,
+            ),
+          ),
+        ),
+      );
+    }
+    await tester.pumpWidget(buildDropdownMenu(requestFocusOnTap: true));
+
+    expect(
+      tester.getSemantics(find.byType(TextField)),
+      matchesSemantics(
+        hasFocusAction: true,
+        hasTapAction: true,
+        isTextField: true,
+        hasEnabledState: true,
+        isEnabled: true,
+        label: 'Test',
+        textDirection: TextDirection.ltr,
+      ),
+    );
+
+    await tester.pumpWidget(buildDropdownMenu(requestFocusOnTap: false));
+
+    expect(
+      tester.getSemantics(find.byType(TextField)),
+      matchesSemantics(
+        hasFocusAction: true,
+        isTextField: true,
+        hasEnabledState: true,
+        isEnabled: true,
+        label: 'Test',
+        isReadOnly: true,
+        textDirection: TextDirection.ltr,
+      ),
+    );
+  });
 }
 
 enum TestMenu {