diff --git a/config/graphql.php b/config/graphql.php
index e2b46d2b411..329c0d463f0 100644
--- a/config/graphql.php
+++ b/config/graphql.php
@@ -27,6 +27,18 @@
         'users' => false,
     ],
 
+    /*
+    |--------------------------------------------------------------------------
+    | Authentication
+    |--------------------------------------------------------------------------
+    |
+    | By default, the GraphQL API will be publicly accessible. However, you
+    | may define an API token here which will be used to authenticate requests.
+    |
+    */
+
+    'auth_token' => env('STATAMIC_GRAPHQL_AUTH_TOKEN'),
+
     /*
     |--------------------------------------------------------------------------
     | Queries
diff --git a/resources/views/graphql/graphiql.blade.php b/resources/views/graphql/graphiql.blade.php
index cff8df91d92..3acaff8d21d 100644
--- a/resources/views/graphql/graphiql.blade.php
+++ b/resources/views/graphql/graphiql.blade.php
@@ -68,6 +68,11 @@
 
             const fetcher = createGraphiQLFetcher({
                 url: '{{ $url }}',
+                @if ($authToken)
+                headers: {
+                    'Authorization': 'Bearer {{ $authToken }}',
+                },
+                @endif
             });
 
             let plugins = [HISTORY_PLUGIN];
diff --git a/src/GraphQL/DefaultSchema.php b/src/GraphQL/DefaultSchema.php
index 1aaed9f1a17..ed2e70278a4 100644
--- a/src/GraphQL/DefaultSchema.php
+++ b/src/GraphQL/DefaultSchema.php
@@ -6,6 +6,7 @@
 use Rebing\GraphQL\Support\Contracts\ConfigConvertible;
 use Statamic\Facades\GraphQL;
 use Statamic\GraphQL\Middleware\CacheResponse;
+use Statamic\GraphQL\Middleware\HandleAuthentication;
 use Statamic\GraphQL\Queries\AssetContainerQuery;
 use Statamic\GraphQL\Queries\AssetContainersQuery;
 use Statamic\GraphQL\Queries\AssetQuery;
@@ -77,7 +78,7 @@ private function getQueries()
     private function getMiddleware()
     {
         return array_merge(
-            [CacheResponse::class],
+            [HandleAuthentication::class, CacheResponse::class],
             config('statamic.graphql.middleware', []),
             GraphQL::getExtraMiddleware()
         );
diff --git a/src/GraphQL/Middleware/HandleAuthentication.php b/src/GraphQL/Middleware/HandleAuthentication.php
new file mode 100644
index 00000000000..ca5ba4e5195
--- /dev/null
+++ b/src/GraphQL/Middleware/HandleAuthentication.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Statamic\GraphQL\Middleware;
+
+use Closure;
+
+class HandleAuthentication
+{
+    /**
+     * Handle an incoming request.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return mixed
+     */
+    public function handle($request, Closure $next)
+    {
+        if (
+            ($token = config('statamic.graphql.auth_token'))
+            && ($request->bearerToken() !== $token)
+        ) {
+            abort(401);
+        }
+
+        return $next($request);
+    }
+}
diff --git a/src/Http/Controllers/CP/GraphQLController.php b/src/Http/Controllers/CP/GraphQLController.php
index 327aaac2f74..25bc5217252 100644
--- a/src/Http/Controllers/CP/GraphQLController.php
+++ b/src/Http/Controllers/CP/GraphQLController.php
@@ -24,6 +24,7 @@ public function graphiql()
         return view('statamic::graphql.graphiql', [
             'url' => '/'.config('graphql.route.prefix'),
             'introspection' => GraphQL::introspectionEnabled(),
+            'authToken' => config('statamic.graphql.auth_token'),
         ]);
     }
 }
diff --git a/tests/Feature/GraphQL/AuthenticationTest.php b/tests/Feature/GraphQL/AuthenticationTest.php
new file mode 100644
index 00000000000..9dd5f5ca0ef
--- /dev/null
+++ b/tests/Feature/GraphQL/AuthenticationTest.php
@@ -0,0 +1,91 @@
+<?php
+
+namespace Tests\Feature\GraphQL;
+
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\Test;
+use Statamic\Facades\Config;
+use Tests\PreventSavingStacheItemsToDisk;
+use Tests\TestCase;
+
+#[Group('graphql')]
+class AuthenticationTest extends TestCase
+{
+    use PreventSavingStacheItemsToDisk;
+
+    #[Test]
+    public function it_can_authenticate_using_auth_token()
+    {
+        Config::set('statamic.graphql.auth_token', 'foobar');
+
+        $this
+            ->withToken('foobar')
+            ->postJson('/graphql', ['query' => '{ping}'])
+            ->assertOk();
+    }
+
+    #[Test]
+    public function it_cant_authenticate_with_invalid_auth_token()
+    {
+        Config::set('statamic.graphql.auth_token', 'foobar');
+
+        $this
+            ->withToken($token = 'invalid')
+            ->postJson($url = '/graphql', ['query' => '{ping}'])
+            ->assertUnauthorized();
+
+        $this
+            ->withToken($token)
+            ->post($url, ['query' => '{ping}'])
+            ->assertUnauthorized();
+    }
+
+    #[Test]
+    public function it_cant_authenticate_without_auth_token()
+    {
+        Config::set('statamic.graphql.auth_token', 'foobar');
+
+        $this
+            ->postJson($url = '/graphql', ['query' => '{ping}'])
+            ->assertUnauthorized();
+
+        $this
+            ->post($url, ['query' => '{ping}'])
+            ->assertUnauthorized();
+    }
+
+    #[Test]
+    public function authentication_only_required_when_auth_token_is_set()
+    {
+        Config::set('statamic.graphql.auth_token', null);
+
+        $this
+            ->postJson($url = '/graphql', ['query' => '{ping}'])
+            ->assertOk();
+
+        $this
+            ->post($url, ['query' => '{ping}'])
+            ->assertOk();
+    }
+
+    #[Test]
+    public function authenticated_responses_are_not_served_to_unauthenticated_requests()
+    {
+        Config::set('statamic.graphql.auth_token', 'foobar');
+        Config::set('statamic.graphql.cache', ['expiry' => 60]);
+
+        // First, make an authenticated request that gets cached
+        $this
+            ->withToken('foobar')
+            ->postJson('/graphql', ['query' => '{ping}'])
+            ->assertOk()
+            ->assertJsonPath('data.ping', 'pong');
+
+        // Now make an unauthenticated request - should get 401, not cached response
+        // This verifies auth happens before caching
+        $this
+            ->withoutToken()
+            ->postJson('/graphql', ['query' => '{ping}'])
+            ->assertUnauthorized();
+    }
+}