diff --git a/Meta/gn/secondary/Userland/Libraries/LibWeb/UIEvents/BUILD.gn b/Meta/gn/secondary/Userland/Libraries/LibWeb/UIEvents/BUILD.gn
index 3526c39fe13c..5b39283cc32e 100644
--- a/Meta/gn/secondary/Userland/Libraries/LibWeb/UIEvents/BUILD.gn
+++ b/Meta/gn/secondary/Userland/Libraries/LibWeb/UIEvents/BUILD.gn
@@ -5,6 +5,7 @@ source_set("UIEvents") {
     "//Userland/",  # For LibGUI needing WindowServer types
   ]
   sources = [
+    "CompositionEvent.cpp",
     "EventNames.cpp",
     "FocusEvent.cpp",
     "InputEvent.cpp",
diff --git a/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni b/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni
index 30b96ea03bf3..dbc18da8d88a 100644
--- a/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni
+++ b/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni
@@ -306,6 +306,7 @@ standard_idl_files = [
   "//Userland/Libraries/LibWeb/SVG/SVGTransformList.idl",
   "//Userland/Libraries/LibWeb/SVG/SVGTSpanElement.idl",
   "//Userland/Libraries/LibWeb/SVG/SVGUseElement.idl",
+  "//Userland/Libraries/LibWeb/UIEvents/CompositionEvent.idl",
   "//Userland/Libraries/LibWeb/UIEvents/FocusEvent.idl",
   "//Userland/Libraries/LibWeb/UIEvents/InputEvent.idl",
   "//Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.idl",
diff --git a/Tests/LibWeb/Text/expected/all-window-properties.txt b/Tests/LibWeb/Text/expected/all-window-properties.txt
index a2bc3f88bf3d..c5da0ec2bb4f 100644
--- a/Tests/LibWeb/Text/expected/all-window-properties.txt
+++ b/Tests/LibWeb/Text/expected/all-window-properties.txt
@@ -51,6 +51,7 @@ Clipboard
 CloseEvent
 CloseWatcher
 Comment
+CompositionEvent
 CountQueuingStrategy
 Crypto
 CryptoKey
diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index fdf4a2292c3a..ab771105efe3 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -666,6 +666,7 @@ set(SOURCES
     SVG/TagNames.cpp
     SVG/ViewBox.cpp
     Selection/Selection.cpp
+    UIEvents/CompositionEvent.cpp
     UIEvents/EventNames.cpp
     UIEvents/FocusEvent.cpp
     UIEvents/InputEvent.cpp
diff --git a/Userland/Libraries/LibWeb/DOM/Document.cpp b/Userland/Libraries/LibWeb/DOM/Document.cpp
index d322505c91c6..1fa25f596e36 100644
--- a/Userland/Libraries/LibWeb/DOM/Document.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Document.cpp
@@ -120,6 +120,7 @@
 #include <LibWeb/SVG/SVGTitleElement.h>
 #include <LibWeb/SVG/TagNames.h>
 #include <LibWeb/Selection/Selection.h>
+#include <LibWeb/UIEvents/CompositionEvent.h>
 #include <LibWeb/UIEvents/EventNames.h>
 #include <LibWeb/UIEvents/FocusEvent.h>
 #include <LibWeb/UIEvents/KeyboardEvent.h>
@@ -1678,7 +1679,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> Document::create_event(StringView i
     if (Infra::is_ascii_case_insensitive_match(interface, "beforeunloadevent"sv)) {
         event = Event::create(realm, FlyString {}); // FIXME: Create BeforeUnloadEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "compositionevent"sv)) {
-        event = Event::create(realm, FlyString {}); // FIXME: Create CompositionEvent
+        event = UIEvents::CompositionEvent::create(realm, String {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "customevent"sv)) {
         event = CustomEvent::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "devicemotionevent"sv)) {
@@ -1708,7 +1709,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> Document::create_event(StringView i
     } else if (Infra::is_ascii_case_insensitive_match(interface, "svgevents"sv)) {
         event = Event::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "textevent"sv)) {
-        event = Event::create(realm, FlyString {}); // FIXME: Create CompositionEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create TextEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "touchevent"sv)) {
         event = Event::create(realm, FlyString {}); // FIXME: Create TouchEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "uievent"sv)
diff --git a/Userland/Libraries/LibWeb/Forward.h b/Userland/Libraries/LibWeb/Forward.h
index 43bb402b7a10..c83b3561e322 100644
--- a/Userland/Libraries/LibWeb/Forward.h
+++ b/Userland/Libraries/LibWeb/Forward.h
@@ -684,6 +684,7 @@ class SVGTitleElement;
 }
 
 namespace Web::UIEvents {
+class CompositionEvent;
 class InputEvent;
 class KeyboardEvent;
 class MouseEvent;
diff --git a/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.cpp b/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.cpp
new file mode 100644
index 000000000000..4409ccf88e37
--- /dev/null
+++ b/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.cpp
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/CompositionEventPrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/UIEvents/CompositionEvent.h>
+
+namespace Web::UIEvents {
+
+JS_DEFINE_ALLOCATOR(CompositionEvent);
+
+JS::NonnullGCPtr<CompositionEvent> CompositionEvent::create(JS::Realm& realm, FlyString const& event_name, CompositionEventInit const& event_init)
+{
+    return realm.heap().allocate<CompositionEvent>(realm, realm, event_name, event_init);
+}
+
+WebIDL::ExceptionOr<JS::NonnullGCPtr<CompositionEvent>> CompositionEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, CompositionEventInit const& event_init)
+{
+    return realm.heap().allocate<CompositionEvent>(realm, realm, event_name, event_init);
+}
+
+CompositionEvent::CompositionEvent(JS::Realm& realm, FlyString const& event_name, CompositionEventInit const& event_init)
+    : UIEvent(realm, event_name, event_init)
+    , m_data(event_init.data)
+{
+}
+
+CompositionEvent::~CompositionEvent() = default;
+
+void CompositionEvent::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(CompositionEvent);
+}
+
+// https://w3c.github.io/uievents/#dom-compositionevent-initcompositionevent
+void CompositionEvent::init_composition_event(String const& type, bool bubbles, bool cancelable, HTML::Window* view, String const& data)
+{
+    // Initializes attributes of a CompositionEvent object. This method has the same behavior as UIEvent.initUIEvent().
+    // The value of detail remains undefined.
+
+    // 1. If this’s dispatch flag is set, then return.
+    if (dispatched())
+        return;
+
+    // 2. Initialize this with type, bubbles, and cancelable.
+    initialize_event(type, bubbles, cancelable);
+
+    // Implementation Defined: Initialise other values.
+    m_view = view;
+    m_data = data;
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.h b/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.h
new file mode 100644
index 000000000000..ce16a87a3104
--- /dev/null
+++ b/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/UIEvents/UIEvent.h>
+
+namespace Web::UIEvents {
+
+struct CompositionEventInit : public UIEventInit {
+    String data;
+};
+
+class CompositionEvent final : public UIEvent {
+    WEB_PLATFORM_OBJECT(CompositionEvent, UIEvent);
+    JS_DECLARE_ALLOCATOR(CompositionEvent);
+
+public:
+    [[nodiscard]] static JS::NonnullGCPtr<CompositionEvent> create(JS::Realm&, FlyString const& event_name, CompositionEventInit const& = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CompositionEvent>> construct_impl(JS::Realm&, FlyString const& event_name, CompositionEventInit const& event_init);
+
+    virtual ~CompositionEvent() override;
+
+    // https://w3c.github.io/uievents/#dom-compositionevent-data
+    String data() const { return m_data; }
+
+    void init_composition_event(String const& type, bool bubbles, bool cancelable, HTML::Window* view, String const& data);
+
+private:
+    CompositionEvent(JS::Realm&, FlyString const& event_name, CompositionEventInit const&);
+
+    virtual void initialize(JS::Realm&) override;
+
+    String m_data;
+};
+
+}
diff --git a/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.idl b/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.idl
new file mode 100644
index 000000000000..cbb147ee996f
--- /dev/null
+++ b/Userland/Libraries/LibWeb/UIEvents/CompositionEvent.idl
@@ -0,0 +1,17 @@
+#import <UIEvents/UIEvent.idl>
+
+// https://w3c.github.io/uievents/#compositionevent
+[Exposed=Window]
+interface CompositionEvent : UIEvent {
+    constructor(DOMString type, optional CompositionEventInit eventInitDict = {});
+    readonly attribute USVString data;
+
+    // https://w3c.github.io/uievents/#dom-compositionevent-initcompositionevent
+    // FIXME: The spec uses WindowProxy rather than Window (spec bug?).
+    undefined initCompositionEvent(DOMString typeArg, optional boolean bubblesArg = false, optional boolean cancelableArg = false, optional Window? viewArg = null, optional DOMString dataArg = "");
+};
+
+// https://w3c.github.io/uievents/#dictdef-compositioneventinit
+dictionary CompositionEventInit : UIEventInit {
+    DOMString data = "";
+};
diff --git a/Userland/Libraries/LibWeb/idl_files.cmake b/Userland/Libraries/LibWeb/idl_files.cmake
index 8af2b9231add..203c6216025c 100644
--- a/Userland/Libraries/LibWeb/idl_files.cmake
+++ b/Userland/Libraries/LibWeb/idl_files.cmake
@@ -296,6 +296,7 @@ libweb_js_bindings(SVG/SVGTransformList)
 libweb_js_bindings(SVG/SVGTSpanElement)
 libweb_js_bindings(SVG/SVGUseElement)
 libweb_js_bindings(Selection/Selection)
+libweb_js_bindings(UIEvents/CompositionEvent)
 libweb_js_bindings(UIEvents/FocusEvent)
 libweb_js_bindings(UIEvents/InputEvent)
 libweb_js_bindings(UIEvents/KeyboardEvent)