diff --git a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp
index 291e4e3bd1b..73607051847 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp
+++ b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -32,4 +33,17 @@ void WorkerNavigator::initialize(JS::Realm& realm)
     WEB_SET_PROTOTYPE_FOR_INTERFACE(WorkerNavigator);
 }
 
+void WorkerNavigator::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_media_capabilities);
+}
+
+JS::NonnullGCPtr<MediaCapabilitiesAPI::MediaCapabilities> WorkerNavigator::media_capabilities()
+{
+    if (!m_media_capabilities)
+        m_media_capabilities = heap().allocate<MediaCapabilitiesAPI::MediaCapabilities>(realm(), realm());
+    return *m_media_capabilities;
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h
index 640a12b9df8..5bbb96ca80f 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h
+++ b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2022, Andrew Kaster <akaster@serenityos.org>
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -11,6 +12,7 @@
 #include <LibWeb/HTML/NavigatorID.h>
 #include <LibWeb/HTML/NavigatorLanguage.h>
 #include <LibWeb/HTML/NavigatorOnLine.h>
+#include <LibWeb/MediaCapabilitiesAPI/MediaCapabilities.h>
 #include <LibWeb/StorageAPI/NavigatorStorage.h>
 
 namespace Web::HTML {
@@ -29,13 +31,19 @@ public:
 
     virtual ~WorkerNavigator() override;
 
+    JS::NonnullGCPtr<MediaCapabilitiesAPI::MediaCapabilities> media_capabilities();
+
 private:
     explicit WorkerNavigator(WorkerGlobalScope&);
 
     virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
 
     // ^StorageAPI::NavigatorStorage
     virtual Bindings::PlatformObject const& this_navigator_storage_object() const override { return *this; }
+
+    // https://w3c.github.io/media-capabilities/#dom-workernavigator-mediacapabilities
+    JS::GCPtr<MediaCapabilitiesAPI::MediaCapabilities> m_media_capabilities;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.idl b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.idl
index 9cdee99fad3..6356f9e6cef 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.idl
+++ b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.idl
@@ -2,11 +2,15 @@
 #import <HTML/NavigatorLanguage.idl>
 #import <HTML/NavigatorOnLine.idl>
 #import <HTML/NavigatorConcurrentHardware.idl>
+#import <MediaCapabilitiesAPI/MediaCapabilities.idl>
 #import <StorageAPI/NavigatorStorage.idl>
 
 // https://html.spec.whatwg.org/multipage/workers.html#workernavigator
 [Exposed=Worker]
-interface WorkerNavigator {};
+interface WorkerNavigator {
+    // https://w3c.github.io/media-capabilities/#dom-workernavigator-mediacapabilities
+    [SameObject] readonly attribute MediaCapabilities mediaCapabilities;
+};
 
 WorkerNavigator includes NavigatorID;
 WorkerNavigator includes NavigatorLanguage;