diff --git a/.changeset/actionmenu2-aria-expanded.md b/.changeset/actionmenu2-aria-expanded.md
new file mode 100644
index 00000000000..be6ca82f9db
--- /dev/null
+++ b/.changeset/actionmenu2-aria-expanded.md
@@ -0,0 +1,5 @@
+---
+'@primer/react': patch
+---
+
+ActionMenu v2: Add aria-expanded to the ActionMenu.Button
diff --git a/docs/content/drafts/ActionMenu2.mdx b/docs/content/drafts/ActionMenu2.mdx
index cdbd5c1cbc6..36d31ff6109 100644
--- a/docs/content/drafts/ActionMenu2.mdx
+++ b/docs/content/drafts/ActionMenu2.mdx
@@ -192,7 +192,7 @@ render(
 
 ### With External Anchor
 
-To create an anchor outside of the menu, you need to switch to controlled mode for the menu and pass it as `anchorRef` to `ActionMenu`:
+To create an anchor outside of the menu, you need to switch to controlled mode for the menu and pass it as `anchorRef` to `ActionMenu`. Make sure you add `aria-expanded` and `aria-haspopup` to the external anchor:
 
 ```javascript live noinline
 // import {ActionMenu, ActionList} from '@primer/react/drafts'
@@ -204,7 +204,7 @@ const Example = () => {
 
   return (
     <>
-      <Button ref={anchorRef} onClick={() => setOpen(!open)}>
+      <Button ref={anchorRef} aria-haspopup="true" aria-expanded={open} onClick={() => setOpen(!open)}>
         {open ? 'Close Menu' : 'Open Menu'}
       </Button>
 
diff --git a/src/AnchoredOverlay/AnchoredOverlay.tsx b/src/AnchoredOverlay/AnchoredOverlay.tsx
index 94c02a4502d..a343c97c3e2 100644
--- a/src/AnchoredOverlay/AnchoredOverlay.tsx
+++ b/src/AnchoredOverlay/AnchoredOverlay.tsx
@@ -156,6 +156,7 @@ export const AnchoredOverlay: React.FC<AnchoredOverlayProps> = ({
           id: anchorId,
           'aria-labelledby': anchorId,
           'aria-haspopup': 'true',
+          'aria-expanded': open,
           tabIndex: 0,
           onClick: onAnchorClick,
           onKeyDown: onAnchorKeyDown
diff --git a/src/__tests__/__snapshots__/ActionMenu.test.tsx.snap b/src/__tests__/__snapshots__/ActionMenu.test.tsx.snap
index 3fe19e10617..760bde79787 100644
--- a/src/__tests__/__snapshots__/ActionMenu.test.tsx.snap
+++ b/src/__tests__/__snapshots__/ActionMenu.test.tsx.snap
@@ -68,6 +68,7 @@ exports[`ActionMenu renders consistently 1`] = `
 }
 
 <button
+  aria-expanded={false}
   aria-haspopup="true"
   aria-label="menu"
   aria-labelledby="react-aria-1"
diff --git a/src/__tests__/__snapshots__/ActionMenu2.test.tsx.snap b/src/__tests__/__snapshots__/ActionMenu2.test.tsx.snap
index 346cf596045..f4821d17679 100644
--- a/src/__tests__/__snapshots__/ActionMenu2.test.tsx.snap
+++ b/src/__tests__/__snapshots__/ActionMenu2.test.tsx.snap
@@ -80,6 +80,7 @@ exports[`ActionMenu renders consistently 1`] = `
   fontFamily="normal"
 >
   <button
+    aria-expanded={false}
     aria-haspopup="true"
     aria-labelledby="react-aria-1"
     className="c1"
diff --git a/src/__tests__/__snapshots__/AnchoredOverlay.test.tsx.snap b/src/__tests__/__snapshots__/AnchoredOverlay.test.tsx.snap
index 12c019b8f61..aedc95f3b47 100644
--- a/src/__tests__/__snapshots__/AnchoredOverlay.test.tsx.snap
+++ b/src/__tests__/__snapshots__/AnchoredOverlay.test.tsx.snap
@@ -80,6 +80,7 @@ exports[`AnchoredOverlay renders consistently 1`] = `
   fontFamily="normal"
 >
   <button
+    aria-expanded={false}
     aria-haspopup="true"
     aria-labelledby="react-aria-1"
     className="c1"
@@ -193,6 +194,7 @@ exports[`AnchoredOverlay should render consistently when open 1`] = `
     font-family="normal"
   >
     <button
+      aria-expanded="true"
       aria-haspopup="true"
       aria-labelledby="react-aria-1"
       class="c1"
diff --git a/src/__tests__/__snapshots__/DropdownMenu.test.tsx.snap b/src/__tests__/__snapshots__/DropdownMenu.test.tsx.snap
index a640314d7b8..1f8b70f0f82 100644
--- a/src/__tests__/__snapshots__/DropdownMenu.test.tsx.snap
+++ b/src/__tests__/__snapshots__/DropdownMenu.test.tsx.snap
@@ -72,6 +72,7 @@ exports[`DropdownMenu renders consistently 1`] = `
 }
 
 <button
+  aria-expanded={false}
   aria-haspopup="true"
   aria-labelledby="react-aria-1"
   className="c0"
diff --git a/src/__tests__/__snapshots__/SelectPanel.test.tsx.snap b/src/__tests__/__snapshots__/SelectPanel.test.tsx.snap
index c24a5619bc6..afdb759c94e 100644
--- a/src/__tests__/__snapshots__/SelectPanel.test.tsx.snap
+++ b/src/__tests__/__snapshots__/SelectPanel.test.tsx.snap
@@ -84,6 +84,7 @@ exports[`SelectPanel renders consistently 1`] = `
   fontFamily="normal"
 >
   <button
+    aria-expanded={false}
     aria-haspopup="true"
     aria-labelledby="react-aria-1"
     className="c1"
diff --git a/src/stories/ActionMenu2.stories.tsx b/src/stories/ActionMenu2.stories.tsx
index 35c7b5dc5a8..7f3d61ec430 100644
--- a/src/stories/ActionMenu2.stories.tsx
+++ b/src/stories/ActionMenu2.stories.tsx
@@ -137,7 +137,7 @@ export function ExternalAnchor(): JSX.Element {
       <h2>External Open State: {open ? 'Open' : 'Closed'}</h2>
       <h2>Last option activated: {actionFired}</h2>
       <div>
-        <Button ref={anchorRef} onClick={() => setOpen(!open)}>
+        <Button ref={anchorRef} onClick={() => setOpen(!open)} aria-expanded={open} aria-haspopup="true">
           {open ? 'Close Menu' : 'Open Menu'}
         </Button>
       </div>