diff --git a/packages/polaris-viz/CHANGELOG.md b/packages/polaris-viz/CHANGELOG.md
index bd5a03f725..9bb896a821 100644
--- a/packages/polaris-viz/CHANGELOG.md
+++ b/packages/polaris-viz/CHANGELOG.md
@@ -5,7 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-<!-- ## Unreleased -->
+## Unreleased
+
+### Changed
+
+- Changed `<StackedAreaChart />` to use a react portal to allow tooltips to render outside the bounds of the chart.
 
 ## [13.2.0] - 2024-05-27
 
diff --git a/packages/polaris-viz/src/components/StackedAreaChart/Chart.tsx b/packages/polaris-viz/src/components/StackedAreaChart/Chart.tsx
index 7514e5335c..823de91cde 100644
--- a/packages/polaris-viz/src/components/StackedAreaChart/Chart.tsx
+++ b/packages/polaris-viz/src/components/StackedAreaChart/Chart.tsx
@@ -6,7 +6,6 @@ import type {
   DataPoint,
   XAxisOptions,
   YAxisOptions,
-  Dimensions,
   BoundingRect,
   LabelFormatter,
 } from '@shopify/polaris-viz-core';
@@ -18,6 +17,7 @@ import {
   COLOR_VISION_SINGLE_ITEM,
   useChartPositions,
   LINE_HEIGHT,
+  clamp,
 } from '@shopify/polaris-viz-core';
 
 import {ChartElements} from '../ChartElements';
@@ -80,7 +80,7 @@ export interface Props {
   theme: string;
   xAxisOptions: Required<XAxisOptions>;
   yAxisOptions: Required<YAxisOptions>;
-  dimensions?: Dimensions;
+  dimensions?: BoundingRect;
   renderLegendContent?: RenderLegendContent;
   renderHiddenLegendLabel?: (count: number) => string;
 }
@@ -127,6 +127,7 @@ export function Chart({
 
   const {
     stackedValues,
+    longestSeriesIndex,
     longestSeriesLength,
     labels: formattedLabels,
   } = useStackedData({
@@ -256,8 +257,8 @@ export function Chart({
   const chartBounds: BoundingRect = {
     width,
     height,
-    x: chartXPosition,
-    y: chartYPosition,
+    x: dimensions?.x ?? chartXPosition,
+    y: dimensions?.y ?? chartYPosition,
   };
 
   const {hasXAxisAnnotations, hasYAxisAnnotations} = checkAvailableAnnotations(
@@ -395,6 +396,7 @@ export function Chart({
           margin={ChartMargin}
           onIndexChange={(index) => setActivePointIndex(index)}
           parentRef={svgRef}
+          usePortal
         />
       )}
 
@@ -424,20 +426,29 @@ export function Chart({
         return TOOLTIP_POSITION_DEFAULT_RETURN;
       }
 
-      const {svgX, svgY} = point;
+      const {svgX} = point;
 
       const closestIndex = Math.round(xScale.invert(svgX - chartXPosition));
 
+      const activeIndex = clamp({
+        amount: closestIndex,
+        min: 0,
+        max: data[longestSeriesIndex].data.length - 1,
+      });
+
       return {
-        x: svgX,
-        y: svgY,
+        x: (event as MouseEvent).pageX,
+        y: (event as MouseEvent).pageY,
         position: TOOLTIP_POSITION,
-        activeIndex: Math.min(longestSeriesLength, closestIndex),
+        activeIndex,
       };
     } else if (index != null) {
+      const activeIndex = index ?? 0;
+      const x = xScale?.(activeIndex) ?? 0;
+
       return {
-        x: xScale?.(index) ?? 0,
-        y: 0,
+        x: x + (dimensions?.x ?? 0),
+        y: dimensions?.y ?? 0,
         position: TOOLTIP_POSITION,
         activeIndex: index,
       };
diff --git a/packages/polaris-viz/src/components/StackedAreaChart/hooks/useStackedData.ts b/packages/polaris-viz/src/components/StackedAreaChart/hooks/useStackedData.ts
index 153acef850..0b188c4c23 100644
--- a/packages/polaris-viz/src/components/StackedAreaChart/hooks/useStackedData.ts
+++ b/packages/polaris-viz/src/components/StackedAreaChart/hooks/useStackedData.ts
@@ -30,5 +30,20 @@ export function useStackedData({data, xAxisOptions}: Props) {
     return Math.max(...stackedValues.map((stack) => stack.length)) - 1;
   }, [stackedValues]);
 
-  return {labels: formattedLabels, longestSeriesLength, stackedValues};
+  const longestSeriesIndex = useMemo(
+    () =>
+      data.reduce((maxIndex, currentSeries, currentIndex) => {
+        return data[maxIndex].data.length < currentSeries.data.length
+          ? currentIndex
+          : maxIndex;
+      }, 0),
+    [data],
+  );
+
+  return {
+    labels: formattedLabels,
+    longestSeriesIndex,
+    longestSeriesLength,
+    stackedValues,
+  };
 }
diff --git a/packages/polaris-viz/src/components/StackedAreaChart/stories/playground/ExternalTooltipPortal.stories.tsx b/packages/polaris-viz/src/components/StackedAreaChart/stories/playground/ExternalTooltipPortal.stories.tsx
new file mode 100644
index 0000000000..27c0431135
--- /dev/null
+++ b/packages/polaris-viz/src/components/StackedAreaChart/stories/playground/ExternalTooltipPortal.stories.tsx
@@ -0,0 +1,52 @@
+import type {Story} from '@storybook/react';
+
+import type {StackedAreaChartProps} from '../../StackedAreaChart';
+import {StackedAreaChart} from '../../StackedAreaChart';
+import {META} from '../meta';
+import {DEFAULT_DATA, DEFAULT_PROPS} from '../data';
+
+export default {
+  ...META,
+  title: `${META.title}/Playground`,
+  decorators: [],
+};
+
+function Card(args: StackedAreaChartProps) {
+  return (
+    <div
+      style={{
+        height: 400,
+        width: 400,
+        background: 'white',
+        borderRadius: '8px',
+        padding: 10,
+      }}
+    >
+      <StackedAreaChart {...args} theme="Uplift" />
+    </div>
+  );
+}
+
+const Template: Story<StackedAreaChartProps> = (
+  args: StackedAreaChartProps,
+) => {
+  return (
+    <div style={{overflow: 'auto'}}>
+      <Card {...args} />
+      <div style={{height: 700, width: 10}} />
+      <div style={{display: 'flex', justifyContent: 'space-between'}}>
+        <Card {...args} />
+        <Card {...args} />
+        <Card {...args} />
+      </div>
+    </div>
+  );
+};
+
+export const ExternalTooltipPortal: Story<StackedAreaChartProps> =
+  Template.bind({});
+
+ExternalTooltipPortal.args = {
+  ...DEFAULT_PROPS,
+  data: DEFAULT_DATA,
+};
diff --git a/packages/polaris-viz/src/components/StackedAreaChart/utilities/getAlteredStackedAreaChartPosition.ts b/packages/polaris-viz/src/components/StackedAreaChart/utilities/getAlteredStackedAreaChartPosition.ts
index b01023770a..264c904ea4 100644
--- a/packages/polaris-viz/src/components/StackedAreaChart/utilities/getAlteredStackedAreaChartPosition.ts
+++ b/packages/polaris-viz/src/components/StackedAreaChart/utilities/getAlteredStackedAreaChartPosition.ts
@@ -1,10 +1,13 @@
 import type {Dimensions} from '@shopify/polaris-viz-core';
+import {clamp} from '@shopify/polaris-viz-core';
 
+import {getRightPosition} from '../../../components/TooltipWrapper';
 import type {TooltipPositionOffset} from '../../TooltipWrapper';
 import type {Margin} from '../../../types';
 
 // The space between the cursor and the tooltip
 const TOOLTIP_MARGIN = 20;
+const SCROLLBAR_WIDTH = 20;
 
 export interface AlteredPositionProps {
   bandwidth: number;
@@ -26,23 +29,18 @@ export type AlteredPosition = (
   props: AlteredPositionProps,
 ) => AlteredPositionReturn;
 
-export function getAlteredStackedAreaChartPosition({
-  currentX,
-  currentY,
-  chartBounds,
-  margin,
-  tooltipDimensions,
-}: AlteredPositionProps): AlteredPositionReturn {
-  const x = Math.min(
-    Math.max(currentX, TOOLTIP_MARGIN),
-    chartBounds.width - tooltipDimensions.width - TOOLTIP_MARGIN,
-  );
+export function getAlteredStackedAreaChartPosition(
+  props: AlteredPositionProps,
+): AlteredPositionReturn {
+  const {currentX, currentY, chartBounds, margin, tooltipDimensions} = props;
+
+  let x = currentX;
+  let y = currentY;
 
   // Y POSITIONING
   // If y is below the chart, adjust the tooltip position to the bottom of the chart
   //
-
-  const y =
+  y =
     currentY >= chartBounds.y + chartBounds.height
       ? chartBounds.height -
         tooltipDimensions.height -
@@ -50,5 +48,40 @@ export function getAlteredStackedAreaChartPosition({
         margin.Bottom
       : currentY;
 
-  return {x, y};
+  // X POSITIONING
+  const right = getRightPosition(x, props);
+  x = right.value;
+
+  if (right.wasOutsideBounds) {
+    const left = getLeftPosition(x);
+    x = left.value;
+  }
+
+  return {
+    x: clamp({
+      amount: x,
+      min: TOOLTIP_MARGIN,
+      max:
+        window.innerWidth -
+        props.tooltipDimensions.width -
+        TOOLTIP_MARGIN -
+        SCROLLBAR_WIDTH,
+    }),
+    y: clamp({
+      amount: y,
+      min: window.scrollY + TOOLTIP_MARGIN,
+      max:
+        window.scrollY +
+        window.innerHeight -
+        props.tooltipDimensions.height -
+        TOOLTIP_MARGIN,
+    }),
+  };
+}
+
+function getLeftPosition(value: number): {
+  value: number;
+  wasOutsideBounds: boolean;
+} {
+  return {value: value - TOOLTIP_MARGIN, wasOutsideBounds: false};
 }
diff --git a/packages/polaris-viz/src/components/StackedAreaChart/utilities/tests/getAlteredStackedAreaChartPosition.test.ts b/packages/polaris-viz/src/components/StackedAreaChart/utilities/tests/getAlteredStackedAreaChartPosition.test.ts
index c01005e5b9..b0f147a09e 100644
--- a/packages/polaris-viz/src/components/StackedAreaChart/utilities/tests/getAlteredStackedAreaChartPosition.test.ts
+++ b/packages/polaris-viz/src/components/StackedAreaChart/utilities/tests/getAlteredStackedAreaChartPosition.test.ts
@@ -22,7 +22,25 @@ const BASE_PROPS: AlteredPositionProps = {
   },
 };
 
+let windowSpy;
+
+function mockWindow({scrollY = 0, innerHeight = 1000, innerWidth = 500}) {
+  windowSpy.mockImplementation(() => ({
+    scrollY,
+    innerHeight,
+    innerWidth,
+  }));
+}
+
 describe('getAlteredStackedAreaChartPosition', () => {
+  beforeEach(() => {
+    windowSpy = jest.spyOn(window, 'window', 'get');
+  });
+
+  afterEach(() => {
+    windowSpy.mockRestore();
+  });
+
   it('returns the original position of y when currentY is within the chart bounds', () => {
     const props = {
       ...BASE_PROPS,
@@ -32,7 +50,6 @@ describe('getAlteredStackedAreaChartPosition', () => {
 
     const result = getAlteredStackedAreaChartPosition(props);
 
-    expect(result.x).toBe(50);
     expect(result.y).toBe(50);
   });
 
@@ -47,8 +64,6 @@ describe('getAlteredStackedAreaChartPosition', () => {
     const margin = props.margin;
     const result = getAlteredStackedAreaChartPosition(props);
 
-    expect(result.x).toBe(20);
-
     expect(result.y).toBe(
       chartBounds.height -
         tooltipDimensions.height -
@@ -68,8 +83,6 @@ describe('getAlteredStackedAreaChartPosition', () => {
     const margin = props.margin;
     const result = getAlteredStackedAreaChartPosition(props);
 
-    expect(result.x).toBe(20);
-
     expect(result.y).toBe(
       chartBounds.height -
         tooltipDimensions.height -
@@ -77,4 +90,34 @@ describe('getAlteredStackedAreaChartPosition', () => {
         margin.Bottom,
     );
   });
+
+  describe('x', () => {
+    it('clamps to the left of a window', () => {
+      mockWindow({
+        scrollY: 0,
+      });
+
+      expect(
+        getAlteredStackedAreaChartPosition({
+          ...BASE_PROPS,
+          currentX: -1000,
+          currentY: 0,
+        }),
+      ).toStrictEqual({x: 20, y: 20});
+    });
+
+    it('clamps to the right of a window', () => {
+      mockWindow({
+        scrollY: 0,
+      });
+
+      expect(
+        getAlteredStackedAreaChartPosition({
+          ...BASE_PROPS,
+          currentX: 1000,
+          currentY: 0,
+        }),
+      ).toStrictEqual({x: 400, y: 20});
+    });
+  });
 });
diff --git a/packages/polaris-viz/src/components/TooltipWrapper/index.ts b/packages/polaris-viz/src/components/TooltipWrapper/index.ts
index 72dea45352..0c96727a0f 100644
--- a/packages/polaris-viz/src/components/TooltipWrapper/index.ts
+++ b/packages/polaris-viz/src/components/TooltipWrapper/index.ts
@@ -6,7 +6,11 @@ export type {
   TooltipPositionOffset,
 } from './types';
 export {TooltipHorizontalOffset, TooltipVerticalOffset} from './types';
-export {getAlteredVerticalBarPosition, TOOLTIP_MARGIN} from './utilities';
+export {
+  getAlteredVerticalBarPosition,
+  getRightPosition,
+  TOOLTIP_MARGIN,
+} from './utilities';
 export type {
   AlteredPositionProps,
   AlteredPositionReturn,