diff --git a/examples/s2-next-macros/src/app/Lazy.js b/examples/s2-next-macros/src/app/Lazy.js
index cd4d1202b2a..b4c10079ddb 100644
--- a/examples/s2-next-macros/src/app/Lazy.js
+++ b/examples/s2-next-macros/src/app/Lazy.js
@@ -109,7 +109,7 @@ export default function Lazy() {
   return (
     <>
       <Section title="Color">
-        <ColorField label="Primary Color" />
+        <ColorField placeholder="-" label="Primary Color" />
         <ColorSwatchPicker>
           <ColorSwatch color="#A00" />
           <ColorSwatch color="#f80" />
@@ -153,16 +153,16 @@ export default function Lazy() {
             <Checkbox value="baseball">Baseball</Checkbox>
             <Checkbox value="basketball">Basketball</Checkbox>
           </CheckboxGroup>
-          <NumberField label="Width" defaultValue={1024} minValue={0} />
+          <NumberField placeholder="Enter a width" label="Width" defaultValue={1024} minValue={0} />
           <RadioGroup label="Favorite pet">
             <Radio value="dogs">Dogs</Radio>
             <Radio value="cats">Cats</Radio>
           </RadioGroup>
           <SearchField label="Search" />
           <Switch>Low power mode</Switch>
-          <TextArea label="Description" />
-          <TextField label="Email" />
-          <TextField label="Password" />
+          <TextArea placeholder="Enter a description" label="Description" />
+          <TextField placeholder="Enter a email" label="Email" />
+          <TextField placeholder="Enter a password" label="Password" />
           <SelectBoxGroup aria-label="Choose a cloud">
             <SelectBox id="aws" textValue="Amazon Web Services">
               <Server />
@@ -359,7 +359,7 @@ export default function Lazy() {
       </Section>
 
       <Section title="Pickers">
-        <ComboBox label="Favorite Animal">
+        <ComboBox placeholder="Select a value" label="Favorite Animal">
           <ComboBoxItem id="red panda">Red Panda</ComboBoxItem>
           <ComboBoxItem id="cat">Cat</ComboBoxItem>
           <ComboBoxItem id="dog">Dog</ComboBoxItem>
diff --git a/examples/s2-parcel-example/src/Lazy.js b/examples/s2-parcel-example/src/Lazy.js
index 43376848858..68b3eb4bc7c 100644
--- a/examples/s2-parcel-example/src/Lazy.js
+++ b/examples/s2-parcel-example/src/Lazy.js
@@ -95,7 +95,7 @@ export default function Lazy() {
   return (
     <>
       <Section title="Color">
-        <ColorField label="Primary Color" />
+        <ColorField placeholder="-" label="Primary Color" />
         <ColorSwatchPicker>
           <ColorSwatch color="#A00" />
           <ColorSwatch color="#f80" />
@@ -139,16 +139,16 @@ export default function Lazy() {
             <Checkbox value="baseball">Baseball</Checkbox>
             <Checkbox value="basketball">Basketball</Checkbox>
           </CheckboxGroup>
-          <NumberField label="Width" defaultValue={1024} minValue={0} />
+          <NumberField placeholder="Enter a width" label="Width" defaultValue={1024} minValue={0} />
           <RadioGroup label="Favorite pet">
             <Radio value="dogs">Dogs</Radio>
             <Radio value="cats">Cats</Radio>
           </RadioGroup>
           <SearchField label="Search" />
           <Switch>Low power mode</Switch>
-          <TextArea label="Description" />
-          <TextField label="Email" />
-          <TextField label="Password" />
+          <TextArea placeholder="Enter a description" label="Description" />
+          <TextField placeholder="Enter a email" label="Email" />
+          <TextField placeholder="Enter a password" label="Password" />
           <SelectBoxGroup aria-label="Choose a cloud">
             <SelectBox id="aws" textValue="Amazon Web Services">
               <Server />
@@ -345,7 +345,7 @@ export default function Lazy() {
       </Section>
 
       <Section title="Pickers">
-        <ComboBox label="Favorite Animal">
+        <ComboBox placeholder="Select a value" label="Favorite Animal">
           <ComboBoxItem id="red panda">Red Panda</ComboBoxItem>
           <ComboBoxItem id="cat">Cat</ComboBoxItem>
           <ComboBoxItem id="dog">Dog</ComboBoxItem>
diff --git a/examples/s2-webpack-5-example/src/Lazy.js b/examples/s2-webpack-5-example/src/Lazy.js
index 43376848858..68b3eb4bc7c 100644
--- a/examples/s2-webpack-5-example/src/Lazy.js
+++ b/examples/s2-webpack-5-example/src/Lazy.js
@@ -95,7 +95,7 @@ export default function Lazy() {
   return (
     <>
       <Section title="Color">
-        <ColorField label="Primary Color" />
+        <ColorField placeholder="-" label="Primary Color" />
         <ColorSwatchPicker>
           <ColorSwatch color="#A00" />
           <ColorSwatch color="#f80" />
@@ -139,16 +139,16 @@ export default function Lazy() {
             <Checkbox value="baseball">Baseball</Checkbox>
             <Checkbox value="basketball">Basketball</Checkbox>
           </CheckboxGroup>
-          <NumberField label="Width" defaultValue={1024} minValue={0} />
+          <NumberField placeholder="Enter a width" label="Width" defaultValue={1024} minValue={0} />
           <RadioGroup label="Favorite pet">
             <Radio value="dogs">Dogs</Radio>
             <Radio value="cats">Cats</Radio>
           </RadioGroup>
           <SearchField label="Search" />
           <Switch>Low power mode</Switch>
-          <TextArea label="Description" />
-          <TextField label="Email" />
-          <TextField label="Password" />
+          <TextArea placeholder="Enter a description" label="Description" />
+          <TextField placeholder="Enter a email" label="Email" />
+          <TextField placeholder="Enter a password" label="Password" />
           <SelectBoxGroup aria-label="Choose a cloud">
             <SelectBox id="aws" textValue="Amazon Web Services">
               <Server />
@@ -345,7 +345,7 @@ export default function Lazy() {
       </Section>
 
       <Section title="Pickers">
-        <ComboBox label="Favorite Animal">
+        <ComboBox placeholder="Select a value" label="Favorite Animal">
           <ComboBoxItem id="red panda">Red Panda</ComboBoxItem>
           <ComboBoxItem id="cat">Cat</ComboBoxItem>
           <ComboBoxItem id="dog">Dog</ComboBoxItem>
diff --git a/packages/@adobe/spectrum-css-temp/components/tray/index.css b/packages/@adobe/spectrum-css-temp/components/tray/index.css
index 30f025ac6d2..0725c8790ca 100644
--- a/packages/@adobe/spectrum-css-temp/components/tray/index.css
+++ b/packages/@adobe/spectrum-css-temp/components/tray/index.css
@@ -55,7 +55,7 @@
   /* Add padding at the bottom to account for the rest of the viewport height behind the keyboard.
    * This is necessary so that there isn't a visible gap that appears while the keyboard is animating
    * in and out. Fall back to the safe area inset to account for things like iOS home indicator.
-     We also add an additional 100vh of padding (offset by the bottom position below) so the tray 
+     We also add an additional 100vh of padding (offset by the bottom position below) so the tray
      extends behind Safari's address bar and keyboard in iOS 26. */
   padding-bottom: calc(max(calc(100dvh - var(--spectrum-visual-viewport-height)), env(safe-area-inset-bottom)) + 100vh);
   position: absolute;
@@ -75,6 +75,8 @@
   /* Exit animations */
   transition: opacity var(--spectrum-dialog-exit-animation-duration) cubic-bezier(0.5, 0, 1, 1) var(--spectrum-dialog-exit-animation-delay),
     transform var(--spectrum-dialog-exit-animation-duration) cubic-bezier(0.5, 0, 1, 1) var(--spectrum-dialog-exit-animation-delay);
+
+  box-sizing: content-box;
 }
 
 .is-open {
diff --git a/packages/@react-aria/combobox/src/useComboBox.ts b/packages/@react-aria/combobox/src/useComboBox.ts
index 1b42aea1daf..5fe460012f0 100644
--- a/packages/@react-aria/combobox/src/useComboBox.ts
+++ b/packages/@react-aria/combobox/src/useComboBox.ts
@@ -16,7 +16,7 @@ import {AriaComboBoxProps} from '@react-types/combobox';
 import {ariaHideOutside} from '@react-aria/overlays';
 import {AriaListBoxOptions, getItemId, listData} from '@react-aria/listbox';
 import {BaseEvent, DOMAttributes, KeyboardDelegate, LayoutDelegate, PressEvent, RefObject, RouterOptions, ValidationResult} from '@react-types/shared';
-import {chain, getActiveElement, getOwnerDocument, isAppleDevice, mergeProps, useLabels, useRouter, useUpdateEffect} from '@react-aria/utils';
+import {chain, getActiveElement, getOwnerDocument, isAppleDevice, mergeProps, useEvent, useLabels, useRouter, useUpdateEffect} from '@react-aria/utils';
 import {ComboBoxState} from '@react-stately/combobox';
 import {dispatchVirtualFocus} from '@react-aria/focus';
 import {FocusEvent, InputHTMLAttributes, KeyboardEvent, TouchEvent, useEffect, useMemo, useRef} from 'react';
@@ -354,6 +354,10 @@ export function useComboBox<T>(props: AriaComboBoxOptions<T>, state: ComboBoxSta
     }
   }, [focusedItem]);
 
+  useEvent(listBoxRef, 'react-aria-item-action', state.isOpen ? () => {
+    state.close();
+  } : undefined);
+
   return {
     labelProps,
     buttonProps: {
@@ -383,7 +387,8 @@ export function useComboBox<T>(props: AriaComboBoxOptions<T>, state: ComboBoxSta
       shouldUseVirtualFocus: true,
       shouldSelectOnPressUp: true,
       shouldFocusOnHover: true,
-      linkBehavior: 'selection' as const
+      linkBehavior: 'selection' as const,
+      ['UNSTABLE_itemBehavior']: 'action'
     }),
     descriptionProps,
     errorMessageProps,
diff --git a/packages/@react-aria/listbox/src/useListBox.ts b/packages/@react-aria/listbox/src/useListBox.ts
index 8774c71bab1..c5ac0984bbf 100644
--- a/packages/@react-aria/listbox/src/useListBox.ts
+++ b/packages/@react-aria/listbox/src/useListBox.ts
@@ -100,7 +100,9 @@ export function useListBox<T>(props: AriaListBoxOptions<T>, state: ListState<T>,
     shouldFocusOnHover: props.shouldFocusOnHover,
     isVirtualized: props.isVirtualized,
     onAction: props.onAction,
-    linkBehavior
+    linkBehavior,
+    // @ts-ignore
+    UNSTABLE_itemBehavior: props['UNSTABLE_itemBehavior']
   });
 
   let {labelProps, fieldProps} = useLabel({
diff --git a/packages/@react-aria/listbox/src/useOption.ts b/packages/@react-aria/listbox/src/useOption.ts
index a8412d1acb6..a2856a8e9dd 100644
--- a/packages/@react-aria/listbox/src/useOption.ts
+++ b/packages/@react-aria/listbox/src/useOption.ts
@@ -137,6 +137,8 @@ export function useOption<T>(props: AriaOptionProps, state: ListState<T>, ref: R
     isDisabled,
     onAction: onAction || item?.props?.onAction ? chain(item?.props?.onAction, onAction) : undefined,
     linkBehavior: data?.linkBehavior,
+    // @ts-ignore
+    UNSTABLE_itemBehavior: data?.['UNSTABLE_itemBehavior'],
     id
   });
 
diff --git a/packages/@react-aria/selection/src/useSelectableItem.ts b/packages/@react-aria/selection/src/useSelectableItem.ts
index 3a892960cf9..cd6107a769b 100644
--- a/packages/@react-aria/selection/src/useSelectableItem.ts
+++ b/packages/@react-aria/selection/src/useSelectableItem.ts
@@ -205,8 +205,9 @@ export function useSelectableItem(options: SelectableItemOptions): SelectableIte
   // With highlight selection, onAction is secondary, and occurs on double click. Single click selects the row.
   // With touch, onAction occurs on single tap, and long press enters selection mode.
   let isLinkOverride = manager.isLink(key) && linkBehavior === 'override';
+  let isActionOverride = onAction && options['UNSTABLE_itemBehavior'] === 'action';
   let hasLinkAction = manager.isLink(key) && linkBehavior !== 'selection' && linkBehavior !== 'none';
-  let allowsSelection = !isDisabled && manager.canSelectItem(key) && !isLinkOverride;
+  let allowsSelection = !isDisabled && manager.canSelectItem(key) && !isLinkOverride && !isActionOverride;
   let allowsActions = (onAction || hasLinkAction) && !isDisabled;
   let hasPrimaryAction = allowsActions && (
     manager.selectionBehavior === 'replace'
@@ -225,6 +226,7 @@ export function useSelectableItem(options: SelectableItemOptions): SelectableIte
   let performAction = (e) => {
     if (onAction) {
       onAction();
+      ref.current?.dispatchEvent(new CustomEvent('react-aria-item-action', {bubbles: true}));
     }
 
     if (hasLinkAction && ref.current) {
diff --git a/packages/@react-spectrum/s2/stories/ComboBox.stories.tsx b/packages/@react-spectrum/s2/stories/ComboBox.stories.tsx
index b4132fab066..73dea75fd1c 100644
--- a/packages/@react-spectrum/s2/stories/ComboBox.stories.tsx
+++ b/packages/@react-spectrum/s2/stories/ComboBox.stories.tsx
@@ -318,6 +318,7 @@ export function WithCreateOption() {
   return (
     <ComboBox
       label="Favorite Animal"
+      placeholder="Select an animal"
       inputValue={inputValue}
       onInputChange={setInputValue}>
       {inputValue.length > 0 && (
diff --git a/packages/react-aria-components/test/ComboBox.test.js b/packages/react-aria-components/test/ComboBox.test.js
index e9b1971a5da..b786271a0da 100644
--- a/packages/react-aria-components/test/ComboBox.test.js
+++ b/packages/react-aria-components/test/ComboBox.test.js
@@ -409,7 +409,7 @@ describe('ComboBox', () => {
     expect(options[0]).toHaveTextContent('No results');
   });
 
-  it('should support onAction', async () => {
+  it.each(['keyboard', 'mouse'])('should support onAction with %s', async (interactionType) => {
     let onAction = jest.fn();
     function WithCreateOption() {
       let [inputValue, setInputValue] = useState('');
@@ -457,8 +457,29 @@ describe('ComboBox', () => {
     expect(options).toHaveLength(1);
     expect(options[0]).toHaveTextContent('Create "L"');
 
-    await user.keyboard('{ArrowDown}{Enter}');
+    if (interactionType === 'keyboard') {
+      await user.keyboard('{ArrowDown}{Enter}');
+    } else {
+      await user.click(options[0]);
+    }
     expect(onAction).toHaveBeenCalledTimes(1);
     expect(comboboxTester.combobox).toHaveValue('');
+    
+    // Repeat with an option selected.
+    await comboboxTester.selectOption({option: 'Cat'});
+
+    await user.keyboard('s');
+
+    options = comboboxTester.options();
+    expect(options).toHaveLength(1);
+    expect(options[0]).toHaveTextContent('Create "Cats"');
+
+    if (interactionType === 'keyboard') {
+      await user.keyboard('{ArrowDown}{Enter}');
+    } else {
+      await user.click(options[0]);
+    }
+    expect(onAction).toHaveBeenCalledTimes(2);
+    expect(comboboxTester.combobox).toHaveValue('Cat');
   });
 });