diff --git a/change/@fluentui-react-positioning-6885ff72-725f-432d-95c5-37ccfe3dba48.json b/change/@fluentui-react-positioning-6885ff72-725f-432d-95c5-37ccfe3dba48.json
new file mode 100644
index 0000000000000..a6c43e61905f2
--- /dev/null
+++ b/change/@fluentui-react-positioning-6885ff72-725f-432d-95c5-37ccfe3dba48.json
@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: Set overflow on positioned element when `autosize` is applied",
+  "packageName": "@fluentui/react-positioning",
+  "email": "lingfangao@hotmail.com",
+  "dependentChangeType": "patch"
+}
diff --git a/packages/react-components/react-positioning/src/middleware/maxSize.ts b/packages/react-components/react-positioning/src/middleware/maxSize.ts
index 1567df6e28a8e..c37ade24333bf 100644
--- a/packages/react-components/react-positioning/src/middleware/maxSize.ts
+++ b/packages/react-components/react-positioning/src/middleware/maxSize.ts
@@ -22,16 +22,18 @@ export function maxSize(autoSize: PositioningOptions['autoSize'], options: MaxSi
         (rects.floating.height > availableHeight && (autoSize === true || autoSize === 'height'));
 
       if (applyMaxHeight) {
-        Object.assign(elements.floating.style, {
+        Object.assign<CSSStyleDeclaration, Partial<CSSStyleDeclaration>>(elements.floating.style, {
           maxHeight: `${availableHeight}px`,
           boxSizing: 'border-box',
+          overflowY: 'auto',
         });
       }
 
       if (applyMaxWidth) {
-        Object.assign(elements.floating.style, {
+        Object.assign<CSSStyleDeclaration, Partial<CSSStyleDeclaration>>(elements.floating.style, {
           maxWidth: `${availableWidth}px`,
           boxSizing: 'border-box',
+          overflowX: 'auto',
         });
       }
     },