diff --git a/common/changes/@itwin/core-react/fix-widgets-popup_2024-11-04-17-06.json b/common/changes/@itwin/core-react/fix-widgets-popup_2024-11-04-17-06.json
new file mode 100644
index 00000000000..80c06088d73
--- /dev/null
+++ b/common/changes/@itwin/core-react/fix-widgets-popup_2024-11-04-17-06.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@itwin/core-react",
+      "comment": "Fix Popup to adjust final position based on container size instead of window size.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@itwin/core-react"
+}
\ No newline at end of file
diff --git a/ui/core-react/src/core-react/popup/Popup.tsx b/ui/core-react/src/core-react/popup/Popup.tsx
index 377d7e9e830..4331ce4cf95 100644
--- a/ui/core-react/src/core-react/popup/Popup.tsx
+++ b/ui/core-react/src/core-react/popup/Popup.tsx
@@ -579,16 +579,16 @@ export class Popup extends React.Component<PopupProps, PopupState> {
       return fittedPoint;
     }
 
-    // const popupRect = this._popup.getBoundingClientRect();
     const { popupWidth, popupHeight } = this._getPopupDimensions();
-    const { innerWidth, innerHeight } = window;
+    const container = this.getContainer();
+    const containerBounds = container.getBoundingClientRect();
 
-    if (fittedPoint.y + popupHeight > innerHeight) {
-      fittedPoint.y = innerHeight - popupHeight;
+    if (fittedPoint.y + popupHeight > containerBounds.height) {
+      fittedPoint.y = containerBounds.height - popupHeight;
     }
 
-    if (fittedPoint.x + popupWidth > innerWidth) {
-      fittedPoint.x = innerWidth - popupWidth;
+    if (fittedPoint.x + popupWidth > containerBounds.width) {
+      fittedPoint.x = containerBounds.width - popupWidth;
     }
 
     if (fittedPoint.y < 0) {
diff --git a/ui/core-react/src/test/popup/Popup.test.tsx b/ui/core-react/src/test/popup/Popup.test.tsx
index 09630d3f288..8b76896ebd6 100644
--- a/ui/core-react/src/test/popup/Popup.test.tsx
+++ b/ui/core-react/src/test/popup/Popup.test.tsx
@@ -494,6 +494,9 @@ describe("<Popup />", () => {
       vi.spyOn(targetElement, "getBoundingClientRect").mockReturnValue(
         DOMRect.fromRect({ x: 100, y: 100, height: 50, width: 50 })
       );
+      vi.spyOn(document.body, "getBoundingClientRect").mockReturnValue(
+        DOMRect.fromRect({ x: 0, y: 0, width: 1000, height: 1000 })
+      );
     });
 
     afterEach(() => {