diff --git a/packages/editor/src/components/provider/index.js b/packages/editor/src/components/provider/index.js
index db74d142899212..46b8cf2c6ca3f8 100644
--- a/packages/editor/src/components/provider/index.js
+++ b/packages/editor/src/components/provider/index.js
@@ -36,6 +36,7 @@ import NavigationBlockEditingMode from './navigation-block-editing-mode';
 import { useHideBlocksFromInserter } from './use-hide-blocks-from-inserter';
 import useCommands from '../commands';
 import useUploadSaveLock from './use-upload-save-lock';
+import useInvalidateMediaAfterUpload from './use-invalidate-media-after-upload';
 import BlockRemovalWarnings from '../block-removal-warnings';
 import StartPageOptions from '../start-page-options';
 import KeyboardShortcutHelpModal from '../keyboard-shortcut-help-modal';
@@ -383,6 +384,9 @@ export const ExperimentalEditorProvider = withRegistryProvider(
 		// Lock post saving when media uploads are in progress (experimental feature).
 		useUploadSaveLock();
 
+		// Invalidate attachment entities after uploads complete so blocks see updated data.
+		useInvalidateMediaAfterUpload();
+
 		if ( ! isReady || ! mode ) {
 			return null;
 		}
diff --git a/packages/editor/src/components/provider/use-invalidate-media-after-upload.js b/packages/editor/src/components/provider/use-invalidate-media-after-upload.js
new file mode 100644
index 00000000000000..b81114492c5196
--- /dev/null
+++ b/packages/editor/src/components/provider/use-invalidate-media-after-upload.js
@@ -0,0 +1,71 @@
+/**
+ * WordPress dependencies
+ */
+import { useSelect, useDispatch } from '@wordpress/data';
+import { useEffect } from '@wordpress/element';
+import { usePrevious } from '@wordpress/compose';
+import { store as uploadStore } from '@wordpress/upload-media';
+import { store as coreDataStore } from '@wordpress/core-data';
+
+const EMPTY_ARRAY = [];
+
+function getAttachmentIds( items ) {
+	const ids = new Set();
+	for ( const item of items ) {
+		if ( item.attachment?.id ) {
+			ids.add( item.attachment.id );
+		}
+	}
+	return ids;
+}
+
+/**
+ * After client-side media processing completes, the entity store has stale
+ * attachment data (empty `media_details.sizes`) because the initial upload
+ * uses `generate_sub_sizes: false`. This hook watches the upload queue and
+ * invalidates each attachment's entity record once its item (including any
+ * sideloads) is removed from the queue, so blocks re-fetch updated data.
+ *
+ * When client-side media processing is not enabled, invalidation is handled
+ * by `receiveEntityRecords` in the `onFileChange` callback of
+ * `packages/editor/src/utils/media-upload/index.js`.
+ */
+export default function useInvalidateMediaAfterUpload() {
+	const items = useSelect( ( select ) => {
+		if ( ! window.__clientSideMediaProcessing ) {
+			return EMPTY_ARRAY;
+		}
+		return select( uploadStore ).getItems();
+	}, [] );
+
+	const previousItems = usePrevious( items );
+	const { invalidateResolution } = useDispatch( coreDataStore );
+
+	useEffect( () => {
+		if ( ! window.__clientSideMediaProcessing || ! previousItems ) {
+			return;
+		}
+
+		const currentIds = getAttachmentIds( items );
+		const previousIds = getAttachmentIds( previousItems );
+
+		for ( const id of previousIds ) {
+			if ( ! currentIds.has( id ) ) {
+				// Invalidate with and without the query argument, since
+				// resolution keys must exactly match the args used by
+				// each consumer's getEntityRecord() call.
+				invalidateResolution( 'getEntityRecord', [
+					'postType',
+					'attachment',
+					id,
+					{ context: 'view' }, // Used by the image block.
+				] );
+				invalidateResolution( 'getEntityRecord', [
+					'postType',
+					'attachment',
+					id, // Used by the editor's mediaUpload onFileChange.
+				] );
+			}
+		}
+	}, [ items, previousItems, invalidateResolution ] );
+}