diff --git a/.changeset/media-upload-failure-reporting.md b/.changeset/media-upload-failure-reporting.md
new file mode 100644
index 000000000..e611864b5
--- /dev/null
+++ b/.changeset/media-upload-failure-reporting.md
@@ -0,0 +1,5 @@
+---
+"@emdash-cms/admin": patch
+---
+
+Fixes the Media Library reporting a failed upload as a success. A rejected upload now shows an error naming the reason, instead of a green "File uploaded" message with nothing added to the list.
diff --git a/packages/admin/src/router.tsx b/packages/admin/src/router.tsx
index c39a32277..dba723fc9 100644
--- a/packages/admin/src/router.tsx
+++ b/packages/admin/src/router.tsx
@@ -1341,7 +1341,9 @@ function MediaPage() {
 			isLoading={isLoading || isFetchingNextPage}
 			hasMore={!!hasNextPage}
 			onLoadMore={() => void fetchNextPage()}
-			onUpload={(file) => uploadMutation.mutate(file)}
+			onUpload={async (file) => {
+				await uploadMutation.mutateAsync(file);
+			}}
 			onLocalSearchChange={setSearch}
 			onLocalMimeFilterChange={setMimeFilter}
 		/>
diff --git a/packages/admin/tests/media-upload-failure.test.tsx b/packages/admin/tests/media-upload-failure.test.tsx
new file mode 100644
index 000000000..a4f4cd737
--- /dev/null
+++ b/packages/admin/tests/media-upload-failure.test.tsx
@@ -0,0 +1,122 @@
+import { Toasty } from "@cloudflare/kumo";
+import { i18n } from "@lingui/core";
+import { I18nProvider } from "@lingui/react";
+import { QueryClientProvider } from "@tanstack/react-query";
+import { RouterProvider } from "@tanstack/react-router";
+import * as React from "react";
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+
+import type { AdminManifest } from "../src/lib/api";
+import { createAdminRouter } from "../src/router";
+import { render } from "./utils/render.tsx";
+import { createMockFetch, createTestQueryClient } from "./utils/test-helpers";
+
+const uploadMedia = vi.fn();
+
+vi.mock("../src/lib/api", async () => {
+	const actual = await vi.importActual("../src/lib/api");
+	return {
+		...actual,
+		fetchMediaList: vi.fn().mockResolvedValue({ items: [], nextCursor: undefined }),
+		uploadMedia: (file: File) => uploadMedia(file) as Promise<unknown>,
+	};
+});
+
+/** Capture the props MediaPage hands to MediaLibrary. */
+let capturedOnUpload: ((file: File) => Promise<void> | void) | undefined;
+
+vi.mock("../src/components/MediaLibrary", () => ({
+	MediaLibrary: (props: { onUpload?: (file: File) => Promise<void> | void }) => {
+		capturedOnUpload = props.onUpload;
+		return <div data-testid="media-library" />;
+	},
+}));
+
+vi.mock("../src/components/Shell", () => ({
+	Shell: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+}));
+
+function buildRouter() {
+	const queryClient = createTestQueryClient();
+	const router = createAdminRouter(queryClient);
+	if (!i18n.locale) {
+		i18n.loadAndActivate({ locale: "en", messages: {} });
+	}
+	function TestApp() {
+		return (
+			<I18nProvider i18n={i18n}>
+				<Toasty>
+					<QueryClientProvider client={queryClient}>
+						<RouterProvider router={router} />
+					</QueryClientProvider>
+				</Toasty>
+			</I18nProvider>
+		);
+	}
+	return { router, TestApp };
+}
+
+async function renderMediaPage() {
+	capturedOnUpload = undefined;
+	const { router, TestApp } = buildRouter();
+	await router.navigate({ to: "/media" });
+	const screen = await render(<TestApp />);
+	await expect.element(screen.getByTestId("media-library")).toBeInTheDocument();
+	return capturedOnUpload;
+}
+
+const MANIFEST: AdminManifest = {
+	version: "1.0.0",
+	hash: "abc123",
+	authMode: "passkey",
+	collections: {},
+	plugins: {},
+	taxonomies: [],
+	i18n: { defaultLocale: "en", locales: ["en"] },
+};
+
+describe("MediaPage upload failure reporting", () => {
+	let mockFetch: ReturnType<typeof createMockFetch>;
+
+	beforeEach(() => {
+		uploadMedia.mockReset();
+		mockFetch = createMockFetch();
+		mockFetch
+			.on("GET", "/_emdash/api/manifest", { data: MANIFEST })
+			.on("GET", "/_emdash/api/auth/me", { data: { id: "user_01", role: 60 } });
+	});
+
+	afterEach(() => {
+		mockFetch.restore();
+	});
+
+	it("rejects when the upload fails, so MediaLibrary can show the error", async () => {
+		uploadMedia.mockRejectedValue(new Error("File type not allowed"));
+
+		const onUpload = await renderMediaPage();
+		expect(onUpload).toBeDefined();
+
+		await expect(
+			Promise.resolve(onUpload?.(new File(["x"], "notes.txt", { type: "text/plain" }))),
+		).rejects.toThrow("File type not allowed");
+	});
+
+	it("resolves when the upload succeeds", async () => {
+		uploadMedia.mockResolvedValue({
+			id: "m1",
+			filename: "photo.png",
+			mimeType: "image/png",
+			url: "/_emdash/api/media/file/m1.png",
+			size: 10,
+			createdAt: "2026-01-01",
+		});
+
+		const onUpload = await renderMediaPage();
+		expect(onUpload).toBeDefined();
+
+		await expect(
+			Promise.resolve(onUpload?.(new File(["x"], "photo.png", { type: "image/png" }))),
+		).resolves.toBeUndefined();
+		expect(uploadMedia).toHaveBeenCalledOnce();
+	});
+});