diff --git a/Tests/LibWeb/Text/expected/Worker/Worker-performance.txt b/Tests/LibWeb/Text/expected/Worker/Worker-performance.txt
new file mode 100644
index 00000000000..d60021025e0
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/Worker/Worker-performance.txt
@@ -0,0 +1 @@
+performance global object is available: true
diff --git a/Tests/LibWeb/Text/input/Worker/Worker-performance.html b/Tests/LibWeb/Text/input/Worker/Worker-performance.html
new file mode 100644
index 00000000000..fe82ace0cc2
--- /dev/null
+++ b/Tests/LibWeb/Text/input/Worker/Worker-performance.html
@@ -0,0 +1,10 @@
+<script src="../include.js"></script>
+<script>
+    asyncTest(done => {
+        let work = new Worker("worker-performance.js");
+        work.onmessage = (evt) => {
+            println(`performance global object is available: ${JSON.stringify(evt.data)}`);
+            done();
+        };
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/Worker/worker-performance.js b/Tests/LibWeb/Text/input/Worker/worker-performance.js
new file mode 100644
index 00000000000..5c3d61c02a2
--- /dev/null
+++ b/Tests/LibWeb/Text/input/Worker/worker-performance.js
@@ -0,0 +1 @@
+postMessage(performance !== undefined);
diff --git a/Userland/Libraries/LibWeb/Animations/DocumentTimeline.cpp b/Userland/Libraries/LibWeb/Animations/DocumentTimeline.cpp
index 08d51b5a9c7..291251069aa 100644
--- a/Userland/Libraries/LibWeb/Animations/DocumentTimeline.cpp
+++ b/Userland/Libraries/LibWeb/Animations/DocumentTimeline.cpp
@@ -19,7 +19,9 @@ JS_DEFINE_ALLOCATOR(DocumentTimeline);
 JS::NonnullGCPtr<DocumentTimeline> DocumentTimeline::create(JS::Realm& realm, DOM::Document& document, HighResolutionTime::DOMHighResTimeStamp origin_time)
 {
     auto timeline = realm.heap().allocate<DocumentTimeline>(realm, realm, document, origin_time);
-    timeline->set_current_time(document.window()->performance()->now());
+    auto* window_or_worker = dynamic_cast<HTML::WindowOrWorkerGlobalScopeMixin*>(&realm.global_object());
+    VERIFY(window_or_worker);
+    timeline->set_current_time(window_or_worker->performance()->now());
     return timeline;
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/Window.cpp b/Userland/Libraries/LibWeb/HTML/Window.cpp
index 63708b28ea4..d05553c099c 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Window.cpp
@@ -58,7 +58,6 @@
 #include <LibWeb/HTML/TraversableNavigable.h>
 #include <LibWeb/HTML/Window.h>
 #include <LibWeb/HTML/WindowProxy.h>
-#include <LibWeb/HighResolutionTime/Performance.h>
 #include <LibWeb/HighResolutionTime/TimeOrigin.h>
 #include <LibWeb/Infra/Base64.h>
 #include <LibWeb/Infra/CharacterTypes.h>
@@ -121,7 +120,6 @@ void Window::visit_edges(JS::Cell::Visitor& visitor)
 
     visitor.visit(m_associated_document);
     visitor.visit(m_current_event);
-    visitor.visit(m_performance);
     visitor.visit(m_screen);
     visitor.visit(m_location);
     visitor.visit(m_crypto);
@@ -1572,14 +1570,6 @@ JS::GCPtr<Selection::Selection> Window::get_selection() const
     return associated_document().get_selection();
 }
 
-// https://w3c.github.io/hr-time/#dom-windoworworkerglobalscope-performance
-JS::NonnullGCPtr<HighResolutionTime::Performance> Window::performance()
-{
-    if (!m_performance)
-        m_performance = heap().allocate<HighResolutionTime::Performance>(realm(), *this);
-    return JS::NonnullGCPtr { *m_performance };
-}
-
 // https://w3c.github.io/webcrypto/#dom-windoworworkerglobalscope-crypto
 JS::NonnullGCPtr<Crypto::Crypto> Window::crypto()
 {
diff --git a/Userland/Libraries/LibWeb/HTML/Window.h b/Userland/Libraries/LibWeb/HTML/Window.h
index c5811ff8e98..ba0a4a1ceed 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.h
+++ b/Userland/Libraries/LibWeb/HTML/Window.h
@@ -196,8 +196,6 @@ public:
 
     JS::GCPtr<Selection::Selection> get_selection() const;
 
-    [[nodiscard]] JS::NonnullGCPtr<HighResolutionTime::Performance> performance();
-
     [[nodiscard]] JS::NonnullGCPtr<Crypto::Crypto> crypto();
 
     [[nodiscard]] JS::NonnullGCPtr<CustomElementRegistry> custom_elements();
@@ -246,7 +244,6 @@ private:
     // https://html.spec.whatwg.org/multipage/webappapis.html#import-maps-allowed
     bool m_import_maps_allowed { true };
 
-    JS::GCPtr<HighResolutionTime::Performance> m_performance;
     JS::GCPtr<Crypto::Crypto> m_crypto;
     JS::GCPtr<CSS::Screen> m_screen;
     JS::GCPtr<Navigator> m_navigator;
diff --git a/Userland/Libraries/LibWeb/HTML/Window.idl b/Userland/Libraries/LibWeb/HTML/Window.idl
index 48d89696480..9de543783a9 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.idl
+++ b/Userland/Libraries/LibWeb/HTML/Window.idl
@@ -5,7 +5,6 @@
 #import <DOM/Document.idl>
 #import <DOM/EventHandler.idl>
 #import <DOM/EventTarget.idl>
-#import <HighResolutionTime/Performance.idl>
 #import <HTML/AnimationFrameProvider.idl>
 #import <HTML/CustomElements/CustomElementRegistry.idl>
 #import <HTML/History.idl>
@@ -106,10 +105,6 @@ interface Window : EventTarget {
     // https://w3c.github.io/selection-api/#extensions-to-window-interface
     Selection? getSelection();
 
-    // FIXME: Everything from here on should be shared through WindowOrWorkerGlobalScope
-    // https://w3c.github.io/hr-time/#the-performance-attribute
-    [Replaceable] readonly attribute Performance performance;
-
     // https://w3c.github.io/webcrypto/#crypto-interface
     [SameObject] readonly attribute Crypto crypto;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp
index c930cc9f261..b55f66b2694 100644
--- a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp
+++ b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp
@@ -25,6 +25,7 @@
 #include <LibWeb/HTML/Timer.h>
 #include <LibWeb/HTML/Window.h>
 #include <LibWeb/HTML/WindowOrWorkerGlobalScope.h>
+#include <LibWeb/HighResolutionTime/Performance.h>
 #include <LibWeb/HighResolutionTime/SupportedPerformanceTypes.h>
 #include <LibWeb/Infra/Base64.h>
 #include <LibWeb/PerformanceTimeline/EntryTypes.h>
@@ -57,6 +58,7 @@ void WindowOrWorkerGlobalScopeMixin::initialize(JS::Realm&)
 
 void WindowOrWorkerGlobalScopeMixin::visit_edges(JS::Cell::Visitor& visitor)
 {
+    visitor.visit(m_performance);
     for (auto& it : m_timers)
         visitor.visit(it.value);
     for (auto& observer : m_registered_performance_observer_objects)
@@ -585,4 +587,12 @@ void WindowOrWorkerGlobalScopeMixin::run_steps_after_a_timeout_impl(i32 timeout,
     timer->start();
 }
 
+// https://w3c.github.io/hr-time/#dom-windoworworkerglobalscope-performance
+JS::NonnullGCPtr<HighResolutionTime::Performance> WindowOrWorkerGlobalScopeMixin::performance()
+{
+    if (!m_performance)
+        m_performance = this_impl().heap().allocate<HighResolutionTime::Performance>(this_impl().realm(), *this);
+    return JS::NonnullGCPtr { *m_performance };
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h
index 6074b8160ec..4071e859cc6 100644
--- a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h
+++ b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h
@@ -63,6 +63,8 @@ public:
 
     void run_steps_after_a_timeout(i32 timeout, Function<void()> completion_step);
 
+    [[nodiscard]] JS::NonnullGCPtr<HighResolutionTime::Performance> performance();
+
 protected:
     void initialize(JS::Realm&);
     void visit_edges(JS::Cell::Visitor&);
@@ -91,6 +93,8 @@ private:
     // a performance entry buffer map map, keyed on a DOMString, representing the entry type to which the buffer belongs. The map's value is the following tuple:
     // NOTE: See the PerformanceEntryTuple struct above for the map's value tuple.
     OrderedHashMap<FlyString, PerformanceTimeline::PerformanceEntryTuple> m_performance_entry_buffer_map;
+
+    JS::GCPtr<HighResolutionTime::Performance> m_performance;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.idl b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.idl
index fda12c65dd2..9dd6938ae8c 100644
--- a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.idl
+++ b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.idl
@@ -1,5 +1,6 @@
 #import <Fetch/Request.idl>
 #import <Fetch/Response.idl>
+#import <HighResolutionTime/Performance.idl>
 #import <HTML/MessagePort.idl>
 
 // FIXME: Support VoidFunction in the IDL parser
@@ -38,4 +39,7 @@ interface mixin WindowOrWorkerGlobalScope {
 
     // https://fetch.spec.whatwg.org/#fetch-method
     [NewObject] Promise<Response> fetch(RequestInfo input, optional RequestInit init = {});
+
+    // https://w3c.github.io/hr-time/#the-performance-attribute
+    [Replaceable] readonly attribute Performance performance;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.h b/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.h
index 3fc8ac5f555..e5263e49ee4 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.h
+++ b/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.h
@@ -51,6 +51,7 @@ public:
     using WindowOrWorkerGlobalScopeMixin::clear_interval;
     using WindowOrWorkerGlobalScopeMixin::clear_timeout;
     using WindowOrWorkerGlobalScopeMixin::fetch;
+    using WindowOrWorkerGlobalScopeMixin::performance;
     using WindowOrWorkerGlobalScopeMixin::queue_microtask;
     using WindowOrWorkerGlobalScopeMixin::set_interval;
     using WindowOrWorkerGlobalScopeMixin::set_timeout;
diff --git a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
index bd208624e76..9e54cd96a18 100644
--- a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
+++ b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
@@ -20,9 +20,9 @@ namespace Web::HighResolutionTime {
 
 JS_DEFINE_ALLOCATOR(Performance);
 
-Performance::Performance(HTML::Window& window)
-    : DOM::EventTarget(window.realm())
-    , m_window(window)
+Performance::Performance(HTML::WindowOrWorkerGlobalScopeMixin& window_or_worker)
+    : DOM::EventTarget(window_or_worker.this_impl().realm())
+    , m_window_or_worker(window_or_worker)
     , m_timer(Core::TimerType::Precise)
 {
     m_timer.start();
@@ -39,14 +39,14 @@ void Performance::initialize(JS::Realm& realm)
 void Performance::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
-    visitor.visit(m_window);
     visitor.visit(m_timing);
+    visitor.visit(m_window_or_worker->this_impl());
 }
 
 JS::GCPtr<NavigationTiming::PerformanceTiming> Performance::timing()
 {
     if (!m_timing)
-        m_timing = heap().allocate<NavigationTiming::PerformanceTiming>(realm(), *m_window);
+        m_timing = heap().allocate<NavigationTiming::PerformanceTiming>(realm(), *m_window_or_worker);
     return m_timing;
 }
 
diff --git a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h
index 213dbeeef30..df748126837 100644
--- a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h
+++ b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h
@@ -9,6 +9,7 @@
 
 #include <LibCore/ElapsedTimer.h>
 #include <LibWeb/DOM/EventTarget.h>
+#include <LibWeb/HTML/WindowOrWorkerGlobalScope.h>
 #include <LibWeb/UserTiming/PerformanceMark.h>
 #include <LibWeb/UserTiming/PerformanceMeasure.h>
 
@@ -36,7 +37,7 @@ public:
     WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> get_entries_by_name(String const& name, Optional<String> type) const;
 
 private:
-    explicit Performance(HTML::Window&);
+    explicit Performance(HTML::WindowOrWorkerGlobalScopeMixin&);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
@@ -44,7 +45,7 @@ private:
     WebIDL::ExceptionOr<HighResolutionTime::DOMHighResTimeStamp> convert_name_to_timestamp(JS::Realm& realm, String const& name);
     WebIDL::ExceptionOr<HighResolutionTime::DOMHighResTimeStamp> convert_mark_to_timestamp(JS::Realm& realm, Variant<String, HighResolutionTime::DOMHighResTimeStamp> mark);
 
-    JS::NonnullGCPtr<HTML::Window> m_window;
+    JS::NonnullGCPtr<HTML::WindowOrWorkerGlobalScopeMixin> m_window_or_worker;
     JS::GCPtr<NavigationTiming::PerformanceTiming> m_timing;
 
     Core::ElapsedTimer m_timer;
diff --git a/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.cpp b/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.cpp
index c3a4260c6f9..705be16612e 100644
--- a/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.cpp
+++ b/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.cpp
@@ -10,9 +10,9 @@ namespace Web::NavigationTiming {
 
 JS_DEFINE_ALLOCATOR(PerformanceTiming);
 
-PerformanceTiming::PerformanceTiming(HTML::Window& window)
-    : PlatformObject(window.realm())
-    , m_window(window)
+PerformanceTiming::PerformanceTiming(HTML::WindowOrWorkerGlobalScopeMixin& window_or_worker)
+    : PlatformObject(window_or_worker.this_impl().realm())
+    , m_window_or_worker(window_or_worker)
 {
 }
 
@@ -27,7 +27,8 @@ void PerformanceTiming::initialize(JS::Realm& realm)
 void PerformanceTiming::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
-    visitor.visit(m_window);
+    if (m_window_or_worker)
+        visitor.visit(m_window_or_worker->this_impl());
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.h b/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.h
index 0c9798d9e07..c92db2e8d2f 100644
--- a/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.h
+++ b/Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.h
@@ -42,12 +42,12 @@ public:
     u64 load_event_end() { return 0; }
 
 private:
-    explicit PerformanceTiming(HTML::Window&);
+    explicit PerformanceTiming(HTML::WindowOrWorkerGlobalScopeMixin&);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
 
-    JS::GCPtr<HTML::Window> m_window;
+    JS::GCPtr<HTML::WindowOrWorkerGlobalScopeMixin> m_window_or_worker;
 };
 
 }