diff --git a/src/components/Tooltip/Tooltip.tsx b/src/components/Tooltip/Tooltip.tsx
index e7b502812..09805ea8f 100644
--- a/src/components/Tooltip/Tooltip.tsx
+++ b/src/components/Tooltip/Tooltip.tsx
@@ -127,6 +127,9 @@ function TooltipContent({
   // Label tooltips are kept in the DOM even when not visually open
   if (!open && purpose !== "label") return null;
 
+  // Hide the tooltip if it has escaped its boundary (when `boundary` prop is set)
+  const escaped = floatingContext.middlewareData?.hide?.escaped ?? false;
+
   return (
     <FloatingPortal>
       <div
@@ -135,7 +138,7 @@ function TooltipContent({
         {...rest.tooltipProps}
         {...rest.getFloatingProps()}
         className={classNames(styles.tooltip, {
-          [styles.invisible]: purpose === "label" && !open,
+          [styles.invisible]: (purpose === "label" && !open) || escaped,
         })}
       >
         <FloatingArrow
diff --git a/src/components/Tooltip/useTooltip.ts b/src/components/Tooltip/useTooltip.ts
index 360c830dc..22479a9ba 100644
--- a/src/components/Tooltip/useTooltip.ts
+++ b/src/components/Tooltip/useTooltip.ts
@@ -9,6 +9,7 @@ import {
   arrow,
   autoUpdate,
   flip,
+  hide,
   offset,
   type OpenChangeReason,
   type Placement,
@@ -77,6 +78,17 @@ export interface CommonUseTooltipProps {
    */
   isTriggerInteractive: boolean;
 
+  /**
+   * An optional boundary element to constrain the tooltip within.
+   * When provided, the tooltip will be hidden if it escapes this boundary.
+   * Also passed to the `flip` middleware so it can choose a placement that
+   * keeps the tooltip inside the boundary.
+   * Accepts a single Element or an array of Elements. Useful for tooltips
+   * near containers they should not overlap (e.g. the message composer).
+   * @default undefined
+   */
+  boundary?: Element | Element[];
+
   /**
    * Additional aria-* attributes to pass through to the floating tooltip for
    * edge cases which require more user awareness like errors & alerts.
@@ -111,6 +123,7 @@ export function useTooltip({
   caption,
   "aria-atomic": ariaAtomic,
   "aria-live": ariaLive,
+  boundary,
   ...props
 }: UseTooltipProps) {
   const labelId = useId();
@@ -143,8 +156,14 @@ export function useTooltip({
         crossAxis: placement.includes("-"),
         fallbackAxisSideDirection: "start",
         padding: 5,
+        boundary,
       }),
       shift({ padding: 5 }),
+      hide({
+        strategy: "escaped",
+        boundary,
+        padding: 6,
+      }),
       // add the little arrow along with the floating content
       arrow({
         element: arrowRef,