diff --git a/Userland/Libraries/LibWeb/CSS/FontFaceSet.cpp b/Userland/Libraries/LibWeb/CSS/FontFaceSet.cpp
index 281f744eb52..cfd0dcafd5c 100644
--- a/Userland/Libraries/LibWeb/CSS/FontFaceSet.cpp
+++ b/Userland/Libraries/LibWeb/CSS/FontFaceSet.cpp
@@ -97,6 +97,18 @@ WebIDL::CallbackType* FontFaceSet::onloading()
     return event_handler_attribute(HTML::EventNames::loading);
 }
 
+// https://drafts.csswg.org/css-font-loading/#dom-fontfaceset-onloadingdone
+void FontFaceSet::set_onloadingdone(WebIDL::CallbackType* event_handler)
+{
+    set_event_handler_attribute(HTML::EventNames::loadingdone, event_handler);
+}
+
+// https://drafts.csswg.org/css-font-loading/#dom-fontfaceset-onloadingdone
+WebIDL::CallbackType* FontFaceSet::onloadingdone()
+{
+    return event_handler_attribute(HTML::EventNames::loadingdone);
+}
+
 // https://drafts.csswg.org/css-font-loading/#dom-fontfaceset-load
 JS::ThrowCompletionOr<JS::NonnullGCPtr<JS::Promise>> FontFaceSet::load(String const&, String const&)
 {
diff --git a/Userland/Libraries/LibWeb/CSS/FontFaceSet.h b/Userland/Libraries/LibWeb/CSS/FontFaceSet.h
index db385a9a14a..a4bc69a4734 100644
--- a/Userland/Libraries/LibWeb/CSS/FontFaceSet.h
+++ b/Userland/Libraries/LibWeb/CSS/FontFaceSet.h
@@ -33,6 +33,8 @@ public:
 
     void set_onloading(WebIDL::CallbackType*);
     WebIDL::CallbackType* onloading();
+    void set_onloadingdone(WebIDL::CallbackType*);
+    WebIDL::CallbackType* onloadingdone();
 
     JS::ThrowCompletionOr<JS::NonnullGCPtr<JS::Promise>> load(String const& font, String const& text);
 
diff --git a/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl b/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl
index 36c703f4354..3633e81b948 100644
--- a/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl
+++ b/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl
@@ -26,7 +26,7 @@ interface FontFaceSet : EventTarget {
 
     // events for when loading state changes
     attribute EventHandler onloading;
-    [FIXME] attribute EventHandler onloadingdone;
+    attribute EventHandler onloadingdone;
     [FIXME] attribute EventHandler onloadingerror;
 
     // check and start loads if appropriate
diff --git a/Userland/Libraries/LibWeb/HTML/EventNames.h b/Userland/Libraries/LibWeb/HTML/EventNames.h
index 3255dac5687..83347232711 100644
--- a/Userland/Libraries/LibWeb/HTML/EventNames.h
+++ b/Userland/Libraries/LibWeb/HTML/EventNames.h
@@ -66,6 +66,7 @@ namespace Web::HTML::EventNames {
     __ENUMERATE_HTML_EVENT(loadeddata)               \
     __ENUMERATE_HTML_EVENT(loadedmetadata)           \
     __ENUMERATE_HTML_EVENT(loading)                  \
+    __ENUMERATE_HTML_EVENT(loadingdone)              \
     __ENUMERATE_HTML_EVENT(loadstart)                \
     __ENUMERATE_HTML_EVENT(message)                  \
     __ENUMERATE_HTML_EVENT(messageerror)             \