diff --git a/layout/xul/nsMenuPopupFrame.cpp b/layout/xul/nsMenuPopupFrame.cpp
index 68b85e64e617..7fc041b5ac71 100644
--- a/layout/xul/nsMenuPopupFrame.cpp
+++ b/layout/xul/nsMenuPopupFrame.cpp
@@ -61,6 +61,9 @@
 #ifdef MOZ_WAYLAND
 #  include "mozilla/WidgetUtilsGtk.h"
 #endif /* MOZ_WAYLAND */
+#ifdef XP_MACOSX
+#  include "mozilla/widget/NativeMenuSupport.h"
+#endif
 
 #include "X11UndefineNone.h"
 
@@ -69,6 +72,7 @@ using mozilla::dom::Document;
 using mozilla::dom::Element;
 using mozilla::dom::Event;
 using mozilla::dom::KeyboardEvent;
+using mozilla::widget::NativeMenu;
 
 int8_t nsMenuPopupFrame::sDefaultLevelIsTop = -1;
 
@@ -129,6 +133,12 @@ nsMenuPopupFrame::nsMenuPopupFrame(ComputedStyle* aStyle,
       Preferences::GetBool("ui.panel.default_level_parent", false);
 }  // ctor
 
+nsMenuPopupFrame::~nsMenuPopupFrame() {
+  if (mNativeMenu) {
+    mNativeMenu->RemoveObserver(this);
+  }
+}
+
 void nsMenuPopupFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
                             nsIFrame* aPrevInFlow) {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
@@ -903,6 +913,40 @@ void nsMenuPopupFrame::InitializePopupAtScreen(nsIContent* aTriggerContent,
   mPositionedOffset = 0;
 }
 
+bool nsMenuPopupFrame::InitializePopupAsNativeContextMenu(
+    nsIContent* aTriggerContent, int32_t aXPos, int32_t aYPos) {
+  RefPtr<NativeMenu> menu;
+#ifdef XP_MACOSX
+  if (mContent->IsElement()) {
+    menu = mozilla::widget::NativeMenuSupport::CreateNativeContextMenu(
+        mContent->AsElement());
+  }
+#endif
+  if (!menu) {
+    return false;
+  }
+
+  mTriggerContent = aTriggerContent;
+  mNativeMenu = menu;
+  mPopupState = ePopupClosed;  // Treat native popups as closed.
+  mAnchorContent = nullptr;
+  mScreenRect = nsIntRect(aXPos, aYPos, 0, 0);
+  mXPos = 0;
+  mYPos = 0;
+  mFlip = FlipType_Default;
+  mPopupAnchor = POPUPALIGNMENT_NONE;
+  mPopupAlignment = POPUPALIGNMENT_NONE;
+  mPosition = POPUPPOSITION_UNKNOWN;
+  mIsContextMenu = true;
+  mAdjustOffsetForContextMenu = true;
+  mAnchorType = MenuPopupAnchorType_Point;
+  mPositionedOffset = 0;
+
+  mNativeMenu->AddObserver(this);
+
+  return true;
+}
+
 void nsMenuPopupFrame::InitializePopupAtRect(nsIContent* aTriggerContent,
                                              const nsAString& aPosition,
                                              const nsIntRect& aRect,
@@ -912,6 +956,17 @@ void nsMenuPopupFrame::InitializePopupAtRect(nsIContent* aTriggerContent,
   mScreenRect = aRect;
 }
 
+void nsMenuPopupFrame::ShowNativeMenu() {
+  MOZ_RELEASE_ASSERT(mNativeMenu);
+  bool succeeded = mNativeMenu->ShowAsContextMenu(
+      DesktopPoint::FromUnknownPoint(mScreenRect.TopLeft()));
+  if (!succeeded) {
+    // preventDefault() was called on the popupshowing event.
+    mNativeMenu->RemoveObserver(this);
+    mNativeMenu = nullptr;
+  }
+}
+
 void nsMenuPopupFrame::ShowPopup(bool aIsContextMenu) {
   mIsContextMenu = aIsContextMenu;
 
@@ -953,6 +1008,18 @@ void nsMenuPopupFrame::ShowPopup(bool aIsContextMenu) {
   mShouldAutoPosition = true;
 }
 
+void nsMenuPopupFrame::OnNativeMenuClosed() {
+  if (!mNativeMenu) {
+    return;
+  }
+
+  // The native menu has closed.
+  // Null out mNativeMenu so that we don't keep it (and mContent) alive
+  // unnecessarily, and unregister ourselves first.
+  mNativeMenu->RemoveObserver(this);
+  mNativeMenu = nullptr;
+}
+
 void nsMenuPopupFrame::HidePopup(bool aDeselectMenu, nsPopupState aNewState) {
   NS_ASSERTION(aNewState == ePopupClosed || aNewState == ePopupInvisible,
                "popup being set to unexpected state");
diff --git a/layout/xul/nsMenuPopupFrame.h b/layout/xul/nsMenuPopupFrame.h
index e609914ddd73..ce0915f05c00 100644
--- a/layout/xul/nsMenuPopupFrame.h
+++ b/layout/xul/nsMenuPopupFrame.h
@@ -14,6 +14,7 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/gfx/Types.h"
 #include "mozilla/StaticPrefs_ui.h"
+#include "mozilla/widget/NativeMenu.h"
 #include "nsAtom.h"
 #include "nsGkAtoms.h"
 #include "nsCOMPtr.h"
@@ -167,12 +168,14 @@ class nsXULPopupShownEvent final : public mozilla::Runnable,
 
 class nsMenuPopupFrame final : public nsBoxFrame,
                                public nsMenuParent,
-                               public nsIReflowCallback {
+                               public nsIReflowCallback,
+                               public mozilla::widget::NativeMenu::Observer {
  public:
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS(nsMenuPopupFrame)
 
   explicit nsMenuPopupFrame(ComputedStyle* aStyle, nsPresContext* aPresContext);
+  ~nsMenuPopupFrame();
 
   // nsMenuParent interface
   virtual nsMenuFrame* GetCurrentMenuItem() override;
@@ -317,6 +320,16 @@ class nsMenuPopupFrame final : public nsBoxFrame,
   void InitializePopupAtScreen(nsIContent* aTriggerContent, int32_t aXPos,
                                int32_t aYPos, bool aIsContextMenu);
 
+  // Called if this popup should be displayed as an OS-native context menu.
+  // This is achieved with the help of mNativeMenu.
+  // Returns whether the native context menu was created successfully.
+  bool InitializePopupAsNativeContextMenu(nsIContent* aTriggerContent,
+                                          int32_t aXPos, int32_t aYPos);
+
+  // Must only be called after a call to InitializePopupAsNativeContextMenu
+  // that returned true.
+  void ShowNativeMenu();
+
   // indicate that the popup should be opened
   void ShowPopup(bool aIsContextMenu);
   // indicate that the popup should be hidden. The new state should either be
@@ -443,6 +456,10 @@ class nsMenuPopupFrame final : public nsBoxFrame,
   virtual bool ReflowFinished() override;
   virtual void ReflowCallbackCanceled() override;
 
+  // NativeMenu::Observer
+  void OnNativeMenuOpened() override {}
+  void OnNativeMenuClosed() override;
+
  protected:
   // returns the popup's level.
   nsPopupLevel PopupLevel(bool aIsNoAutoHide) const;
@@ -561,6 +578,11 @@ class nsMenuPopupFrame final : public nsBoxFrame,
  protected:
   nsString mIncrementalString;  // for incremental typing navigation
 
+  // If this popup is displayed as a native menu, this is non-null while the
+  // native menu is open.
+  // mNativeMenu has a strong reference to the menupopup nsIContent.
+  RefPtr<mozilla::widget::NativeMenu> mNativeMenu;
+
   // the content that the popup is anchored to, if any, which may be in a
   // different document than the popup.
   nsCOMPtr<nsIContent> mAnchorContent;
diff --git a/layout/xul/nsXULPopupManager.cpp b/layout/xul/nsXULPopupManager.cpp
index f53c674c0db1..13109f650d41 100644
--- a/layout/xul/nsXULPopupManager.cpp
+++ b/layout/xul/nsXULPopupManager.cpp
@@ -47,6 +47,7 @@
 #include "mozilla/PresShell.h"
 #include "mozilla/Services.h"
 #include "mozilla/StaticPrefs_ui.h"
+#include "mozilla/StaticPrefs_widget.h"
 #include "mozilla/StaticPrefs_xul.h"
 #include "mozilla/widget/nsAutoRollup.h"
 
@@ -708,6 +709,15 @@ void nsXULPopupManager::ShowPopup(nsIContent* aPopup,
                         aTriggerEvent);
 }
 
+static bool ShouldUseNativeContextMenus() {
+#ifdef XP_MACOSX
+  return StaticPrefs::widget_macos_native_context_menus() &&
+         Preferences::GetBool("browser.proton.contextmenus.enabled", false);
+#else
+  return false;
+#endif
+}
+
 void nsXULPopupManager::ShowPopupAtScreen(nsIContent* aPopup, int32_t aXPos,
                                           int32_t aYPos, bool aIsContextMenu,
                                           Event* aTriggerEvent) {
@@ -717,6 +727,15 @@ void nsXULPopupManager::ShowPopupAtScreen(nsIContent* aPopup, int32_t aXPos,
   nsCOMPtr<nsIContent> triggerContent;
   InitTriggerEvent(aTriggerEvent, aPopup, getter_AddRefs(triggerContent));
 
+  if (aIsContextMenu && ShouldUseNativeContextMenus()) {
+    bool haveNativeMenu = popupFrame->InitializePopupAsNativeContextMenu(
+        triggerContent, aXPos, aYPos);
+    if (haveNativeMenu) {
+      popupFrame->ShowNativeMenu();
+      return;
+    }
+  }
+
   popupFrame->InitializePopupAtScreen(triggerContent, aXPos, aYPos,
                                       aIsContextMenu);
   FirePopupShowingEvent(aPopup, aIsContextMenu, false, aTriggerEvent);
diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index 80280dc9791f..85748bc9d45c 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -10829,6 +10829,11 @@
   mirror: always
 
 #ifdef XP_MACOSX
+- name: widget.macos.native-context-menus
+  type: RelaxedAtomicBool
+  value: false
+  mirror: always
+
 - name: widget.macos.respect-system-appearance
   type: RelaxedAtomicBool
   value: false