diff --git a/packages/components/CHANGELOG.md b/packages/components/CHANGELOG.md
index ce151116df5bfb..7865993d4e995f 100644
--- a/packages/components/CHANGELOG.md
+++ b/packages/components/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 -   `BoxControl`: Passive deprecate `onMouseOver`/`onMouseOut`. Pass to the `inputProps` prop instead ([#67332](https://github.com/WordPress/gutenberg/pull/67332)).
 -   `BoxControl`: Deprecate 36px default size ([#66704](https://github.com/WordPress/gutenberg/pull/66704)).
+-   `UnitControl`: Deprecate 36px default size ([#66791](https://github.com/WordPress/gutenberg/pull/66791)).
 
 ### Enhancements
 
diff --git a/packages/components/src/border-control/border-control/component.tsx b/packages/components/src/border-control/border-control/component.tsx
index 2ba338c2bb30cb..f71599b274778d 100644
--- a/packages/components/src/border-control/border-control/component.tsx
+++ b/packages/components/src/border-control/border-control/component.tsx
@@ -75,6 +75,8 @@ const UnconnectedBorderControl = (
 			/>
 			<HStack spacing={ 4 } className={ innerWrapperClassName }>
 				<UnitControl
+					__next40pxDefaultSize={ __next40pxDefaultSize }
+					__shouldNotWarnDeprecated36pxSize
 					prefix={
 						<Spacer marginRight={ 1 } marginBottom={ 0 }>
 							<BorderControlDropdown
diff --git a/packages/components/src/box-control/all-input-control.tsx b/packages/components/src/box-control/all-input-control.tsx
index 057cf3c15d8c38..0cfaea21915f6d 100644
--- a/packages/components/src/box-control/all-input-control.tsx
+++ b/packages/components/src/box-control/all-input-control.tsx
@@ -74,6 +74,7 @@ export default function AllInputControl( {
 		<>
 			<StyledUnitControl
 				{ ...props }
+				__shouldNotWarnDeprecated36pxSize
 				__next40pxDefaultSize={ __next40pxDefaultSize }
 				className="component-box-control__unit-control"
 				disableUnits={ isMixed }
diff --git a/packages/components/src/box-control/axial-input-controls.tsx b/packages/components/src/box-control/axial-input-controls.tsx
index 40b39840b464b5..f8cbc5635c9b55 100644
--- a/packages/components/src/box-control/axial-input-controls.tsx
+++ b/packages/components/src/box-control/axial-input-controls.tsx
@@ -106,6 +106,7 @@ export default function AxialInputControls( {
 						<Tooltip placement="top-end" text={ LABELS[ side ] }>
 							<StyledUnitControl
 								{ ...props }
+								__shouldNotWarnDeprecated36pxSize
 								__next40pxDefaultSize={ __next40pxDefaultSize }
 								className="component-box-control__unit-control"
 								id={ inputId }
diff --git a/packages/components/src/box-control/input-controls.tsx b/packages/components/src/box-control/input-controls.tsx
index 1f005f6c6c01bd..8f4518d717dbed 100644
--- a/packages/components/src/box-control/input-controls.tsx
+++ b/packages/components/src/box-control/input-controls.tsx
@@ -108,6 +108,7 @@ export default function BoxInputControls( {
 						<Tooltip placement="top-end" text={ LABELS[ side ] }>
 							<StyledUnitControl
 								{ ...props }
+								__shouldNotWarnDeprecated36pxSize
 								__next40pxDefaultSize={ __next40pxDefaultSize }
 								className="component-box-control__unit-control"
 								id={ inputId }
diff --git a/packages/components/src/font-size-picker/index.tsx b/packages/components/src/font-size-picker/index.tsx
index a71e60cd6719c8..a47812640f1a29 100644
--- a/packages/components/src/font-size-picker/index.tsx
+++ b/packages/components/src/font-size-picker/index.tsx
@@ -212,6 +212,7 @@ const UnforwardedFontSizePicker = (
 						<FlexItem isBlock>
 							<UnitControl
 								__next40pxDefaultSize={ __next40pxDefaultSize }
+								__shouldNotWarnDeprecated36pxSize
 								label={ __( 'Custom' ) }
 								labelPosition="top"
 								hideLabelFromVision
diff --git a/packages/components/src/tools-panel/stories/index.story.tsx b/packages/components/src/tools-panel/stories/index.story.tsx
index 787585ac716b51..0fbdae794d838d 100644
--- a/packages/components/src/tools-panel/stories/index.story.tsx
+++ b/packages/components/src/tools-panel/stories/index.story.tsx
@@ -74,6 +74,7 @@ export const Default: StoryFn< typeof ToolsPanel > = ( {
 						isShownByDefault
 					>
 						<UnitControl
+							__next40pxDefaultSize
 							label="Width"
 							value={ width }
 							onChange={ ( next ) => setWidth( next ) }
@@ -86,6 +87,7 @@ export const Default: StoryFn< typeof ToolsPanel > = ( {
 						isShownByDefault
 					>
 						<UnitControl
+							__next40pxDefaultSize
 							label="Height"
 							value={ height }
 							onChange={ ( next ) => setHeight( next ) }
@@ -98,6 +100,7 @@ export const Default: StoryFn< typeof ToolsPanel > = ( {
 						isShownByDefault
 					>
 						<UnitControl
+							__next40pxDefaultSize
 							label="Minimum height"
 							value={ minHeight }
 							onChange={ ( next ) => setMinHeight( next ) }
@@ -167,6 +170,7 @@ export const WithNonToolsPanelItems: StoryFn< typeof ToolsPanel > = ( {
 						isShownByDefault
 					>
 						<UnitControl
+							__next40pxDefaultSize
 							label="Width"
 							value={ width }
 							onChange={ ( next ) => setWidth( next ) }
@@ -179,6 +183,7 @@ export const WithNonToolsPanelItems: StoryFn< typeof ToolsPanel > = ( {
 						isShownByDefault
 					>
 						<UnitControl
+							__next40pxDefaultSize
 							label="Height"
 							value={ height }
 							onChange={ ( next ) => setHeight( next ) }
@@ -237,6 +242,7 @@ export const WithOptionalItemsPlusIcon: StoryFn< typeof ToolsPanel > = ( {
 							}
 						>
 							<UnitControl
+								__next40pxDefaultSize
 								label="Minimum width"
 								value={ minWidth }
 								onChange={ ( next ) => setMinWidth( next ) }
@@ -249,6 +255,7 @@ export const WithOptionalItemsPlusIcon: StoryFn< typeof ToolsPanel > = ( {
 							isShownByDefault={ false }
 						>
 							<UnitControl
+								__next40pxDefaultSize
 								label="Width"
 								value={ width }
 								onChange={ ( next ) => setWidth( next ) }
@@ -261,6 +268,7 @@ export const WithOptionalItemsPlusIcon: StoryFn< typeof ToolsPanel > = ( {
 							isShownByDefault={ false }
 						>
 							<UnitControl
+								__next40pxDefaultSize
 								label="Height"
 								value={ height }
 								onChange={ ( next ) => setHeight( next ) }
@@ -341,6 +349,7 @@ export const WithSlotFillItems: StoryFn< typeof ToolsPanel > = ( {
 					panelId={ panelId }
 				>
 					<UnitControl
+						__next40pxDefaultSize
 						label="Injected Width"
 						value={ width }
 						onChange={ ( next ) =>
@@ -356,6 +365,7 @@ export const WithSlotFillItems: StoryFn< typeof ToolsPanel > = ( {
 					panelId={ panelId }
 				>
 					<UnitControl
+						__next40pxDefaultSize
 						label="Injected Height"
 						value={ height }
 						onChange={ ( next ) =>
@@ -441,6 +451,7 @@ export const WithConditionalDefaultControl: StoryFn< typeof ToolsPanel > = ( {
 					isShownByDefault
 				>
 					<UnitControl
+						__next40pxDefaultSize
 						label="Injected Height"
 						value={ height }
 						onChange={ ( next ) =>
@@ -541,6 +552,7 @@ export const WithConditionallyRenderedControl: StoryFn<
 					isShownByDefault
 				>
 					<UnitControl
+						__next40pxDefaultSize
 						label="Injected Height"
 						value={ height }
 						onChange={ ( next ) =>
diff --git a/packages/components/src/tools-panel/tools-panel/README.md b/packages/components/src/tools-panel/tools-panel/README.md
index 1895f5ccc843ec..b5e6860e2bd072 100644
--- a/packages/components/src/tools-panel/tools-panel/README.md
+++ b/packages/components/src/tools-panel/tools-panel/README.md
@@ -101,6 +101,7 @@ export function DimensionPanel() {
 				isShownByDefault
 			>
 				<UnitControl
+					__next40pxDefaultSize
 					label={ __( 'Height' ) }
 					onChange={ setHeight }
 					value={ height }
@@ -113,6 +114,7 @@ export function DimensionPanel() {
 				isShownByDefault
 			>
 				<UnitControl
+					__next40pxDefaultSize
 					label={ __( 'Width' ) }
 					onChange={ setWidth }
 					value={ width }
diff --git a/packages/components/src/tools-panel/tools-panel/component.tsx b/packages/components/src/tools-panel/tools-panel/component.tsx
index 4e01e39ffffb43..c094d593dd4c24 100644
--- a/packages/components/src/tools-panel/tools-panel/component.tsx
+++ b/packages/components/src/tools-panel/tools-panel/component.tsx
@@ -75,6 +75,7 @@ const UnconnectedToolsPanel = (
  *         onDeselect={ () => setHeight() }
  *       >
  *         <UnitControl
+ *           __next40pxDefaultSize
  *           label={ __( 'Height' ) }
  *           onChange={ setHeight }
  *           value={ height }
@@ -86,6 +87,7 @@ const UnconnectedToolsPanel = (
  *         onDeselect={ () => setWidth() }
  *       >
  *         <UnitControl
+ *           __next40pxDefaultSize
  *           label={ __( 'Width' ) }
  *           onChange={ setWidth }
  *           value={ width }
diff --git a/packages/components/src/unit-control/README.md b/packages/components/src/unit-control/README.md
index dd54de80357d8e..65d9e4b74062dd 100644
--- a/packages/components/src/unit-control/README.md
+++ b/packages/components/src/unit-control/README.md
@@ -15,7 +15,7 @@ import { __experimentalUnitControl as UnitControl } from '@wordpress/components'
 const Example = () => {
 	const [ value, setValue ] = useState( '10px' );
 
-	return <UnitControl onChange={ setValue } value={ value } />;
+	return <UnitControl __next40pxDefaultSize onChange={ setValue } value={ value } />;
 };
 ```
 
@@ -128,7 +128,7 @@ const Example = () => {
 	];
 
 	return (
-		<UnitControl onChange={ setValue } value={ value } units={ units } />
+		<UnitControl __next40pxDefaultSize onChange={ setValue } value={ value } units={ units } />
 	);
 };
 ```
@@ -143,7 +143,7 @@ For example, a `value` of `50%` will set the current unit to `%`.
 Example:
 
 ```jsx
-<UnitControl value="50%" />
+<UnitControl __next40pxDefaultSize value="50%" />
 ```
 
 -   Required: No
diff --git a/packages/components/src/unit-control/index.tsx b/packages/components/src/unit-control/index.tsx
index 2dd08cc155225f..9845c4eb04ef26 100644
--- a/packages/components/src/unit-control/index.tsx
+++ b/packages/components/src/unit-control/index.tsx
@@ -27,6 +27,7 @@ import { useControlledState } from '../utils/hooks';
 import { escapeRegExp } from '../utils/strings';
 import type { UnitControlProps, UnitControlOnChangeCallback } from './types';
 import { useDeprecated36pxDefaultSizeProp } from '../utils/use-deprecated-props';
+import { maybeWarnDeprecated36pxSize } from '../utils/deprecated-36px-size';
 
 function UnforwardedUnitControl(
 	unitControlProps: WordPressComponentProps<
@@ -55,9 +56,17 @@ function UnforwardedUnitControl(
 		units: unitsProp = CSS_UNITS,
 		value: valueProp,
 		onFocus: onFocusProp,
+		__shouldNotWarnDeprecated36pxSize,
 		...props
 	} = useDeprecated36pxDefaultSizeProp( unitControlProps );
 
+	maybeWarnDeprecated36pxSize( {
+		componentName: 'UnitControl',
+		__next40pxDefaultSize: props.__next40pxDefaultSize,
+		size,
+		__shouldNotWarnDeprecated36pxSize,
+	} );
+
 	if ( 'unit' in unitControlProps ) {
 		deprecated( 'UnitControl unit prop', {
 			since: '5.6',
@@ -246,7 +255,7 @@ function UnforwardedUnitControl(
  * const Example = () => {
  *   const [ value, setValue ] = useState( '10px' );
  *
- *   return <UnitControl onChange={ setValue } value={ value } />;
+ *   return <UnitControl __next40pxDefaultSize onChange={ setValue } value={ value } />;
  * };
  * ```
  */
diff --git a/packages/components/src/unit-control/stories/index.story.tsx b/packages/components/src/unit-control/stories/index.story.tsx
index de8f476e26e5c7..87628c46441169 100644
--- a/packages/components/src/unit-control/stories/index.story.tsx
+++ b/packages/components/src/unit-control/stories/index.story.tsx
@@ -59,6 +59,7 @@ export const Default: StoryFn< typeof UnitControl > = DefaultTemplate.bind(
 );
 Default.args = {
 	label: 'Label',
+	__next40pxDefaultSize: true,
 };
 
 /**
diff --git a/packages/components/src/unit-control/test/index.tsx b/packages/components/src/unit-control/test/index.tsx
index d91498d46478b3..ad98d57cae6405 100644
--- a/packages/components/src/unit-control/test/index.tsx
+++ b/packages/components/src/unit-control/test/index.tsx
@@ -12,9 +12,13 @@ import { useState } from '@wordpress/element';
 /**
  * Internal dependencies
  */
-import UnitControl from '..';
+import _UnitControl from '..';
 import { CSS_UNITS, parseQuantityAndUnitFromRawValue } from '../utils';
 
+const UnitControl = ( props: React.ComponentProps< typeof _UnitControl > ) => (
+	<_UnitControl __next40pxDefaultSize { ...props } />
+);
+
 const getInput = ( {
 	isInputTypeText = false,
 }: {
diff --git a/packages/components/src/unit-control/types.ts b/packages/components/src/unit-control/types.ts
index 9164502668a2b0..891945b422862a 100644
--- a/packages/components/src/unit-control/types.ts
+++ b/packages/components/src/unit-control/types.ts
@@ -107,4 +107,11 @@ export type UnitControlProps = Pick< InputControlProps, 'size' > &
 		 * Callback when either the quantity or the unit inputs gains focus.
 		 */
 		onFocus?: FocusEventHandler< HTMLInputElement | HTMLSelectElement >;
+		/**
+		 * Do not throw a warning for the deprecated 36px default size.
+		 * For internal components of other components that already throw the warning.
+		 *
+		 * @ignore
+		 */
+		__shouldNotWarnDeprecated36pxSize?: boolean;
 	};