diff --git a/.changeset/tough-ears-drive.md b/.changeset/tough-ears-drive.md
new file mode 100644
index 00000000000..7cb54e4143e
--- /dev/null
+++ b/.changeset/tough-ears-drive.md
@@ -0,0 +1,5 @@
+---
+'@primer/react': patch
+---
+
+ActionList.Item: fix inline descriptions being referenced via `aria-labelledby` instead of `aria-describedby`
diff --git a/packages/react/src/ActionList/ActionList.test.tsx b/packages/react/src/ActionList/ActionList.test.tsx
index 6def3de94f5..49e44022c7f 100644
--- a/packages/react/src/ActionList/ActionList.test.tsx
+++ b/packages/react/src/ActionList/ActionList.test.tsx
@@ -203,6 +203,42 @@ describe('ActionList', () => {
     expect(descriptions[2]).not.toHaveAttribute('title')
   })
 
+  it('references inline description via aria-describedby', () => {
+    const {container} = HTMLRender(
+      <ActionList role="listbox" selectionVariant="single" aria-label="List">
+        <ActionList.Item role="option">
+          Item label
+          <ActionList.Description>Inline description</ActionList.Description>
+        </ActionList.Item>
+      </ActionList>,
+    )
+
+    const item = container.querySelector('[role="option"]')!
+    const descriptionEl = container.querySelector('[data-component="ActionList.Description"]')!
+    const descriptionId = descriptionEl.getAttribute('id')!
+
+    expect(item.getAttribute('aria-describedby')).toContain(descriptionId)
+    expect(item.getAttribute('aria-labelledby')).not.toContain(descriptionId)
+  })
+
+  it('references block description via aria-describedby', () => {
+    const {container} = HTMLRender(
+      <ActionList role="listbox" selectionVariant="single" aria-label="List">
+        <ActionList.Item role="option">
+          Item label
+          <ActionList.Description variant="block">Block description</ActionList.Description>
+        </ActionList.Item>
+      </ActionList>,
+    )
+
+    const item = container.querySelector('[role="option"]')!
+    const descriptionEl = container.querySelector('[data-component="ActionList.Description"]')!
+    const descriptionId = descriptionEl.getAttribute('id')!
+
+    expect(item.getAttribute('aria-describedby')).toContain(descriptionId)
+    expect(item.getAttribute('aria-labelledby')).not.toContain(descriptionId)
+  })
+
   it('should support size prop on LinkItem', () => {
     const {container} = HTMLRender(
       <ActionList>
diff --git a/packages/react/src/ActionList/Item.tsx b/packages/react/src/ActionList/Item.tsx
index e6625ca0cdf..765fd27d7c5 100644
--- a/packages/react/src/ActionList/Item.tsx
+++ b/packages/react/src/ActionList/Item.tsx
@@ -232,16 +232,16 @@ const UnwrappedItem = <As extends React.ElementType = 'li'>(
   const ariaLabelledBy = React.useMemo(() => {
     const parts = [labelId]
     if (hasTrailingVisualSlot) parts.push(trailingVisualId)
-    if (hasDescriptionSlot && descriptionVariant === 'inline') parts.push(inlineDescriptionId)
     return parts.join(' ')
-  }, [labelId, hasTrailingVisualSlot, trailingVisualId, hasDescriptionSlot, descriptionVariant, inlineDescriptionId])
+  }, [labelId, hasTrailingVisualSlot, trailingVisualId])
 
   const ariaDescribedBy = React.useMemo(() => {
     const parts: string[] = []
     if (hasDescriptionSlot && descriptionVariant === 'block') parts.push(blockDescriptionId)
+    if (hasDescriptionSlot && descriptionVariant === 'inline') parts.push(inlineDescriptionId)
     if (inactiveWarningId) parts.push(inactiveWarningId)
     return parts.length > 0 ? parts.join(' ') : undefined
-  }, [hasDescriptionSlot, descriptionVariant, blockDescriptionId, inactiveWarningId])
+  }, [hasDescriptionSlot, descriptionVariant, blockDescriptionId, inlineDescriptionId, inactiveWarningId])
 
   const menuItemProps = React.useMemo(
     () => ({