diff --git a/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php b/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php
index c4b6935142dc3..6d63556cb1e29 100644
--- a/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php
+++ b/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php
@@ -967,6 +967,18 @@ protected static function compute_style_properties( $styles, $settings = array()
 				continue;
 			}
 
+			// Calculates fluid typography rules where available.
+			if ( 'font-size' === $css_property ) {
+				/*
+				 * gutenberg_get_typography_font_size_value() will check
+				 * if fluid typography has been activated and also
+				 * whether the incoming value can be converted to a fluid value.
+				 * Values that already have a "clamp()" function will not pass the test,
+				 * and therefore the original $value will be returned.
+				 */
+				$value = gutenberg_get_typography_font_size_value( array( 'size' => $value ) );
+			}
+
 			$declarations[] = array(
 				'name'  => $css_property,
 				'value' => $value,
diff --git a/packages/components/CHANGELOG.md b/packages/components/CHANGELOG.md
index 7cece0b1abf53..31ad5b0457d7e 100644
--- a/packages/components/CHANGELOG.md
+++ b/packages/components/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 ### Bug Fix
 
+-   `FontSizePicker`: Ensure that fluid font size presets appear correctly in the UI controls ([#44791](https://github.com/WordPress/gutenberg/pull/44791))
 -   The `LinkedButton` to unlink sides in `BoxControl`, `BorderBoxControl` and `BorderRadiusControl` have changed from a rectangular primary button to an icon-only button, with a sentence case tooltip, and default-size icon for better legibility. The `Button` component has been fixed so when `isSmall` and `icon` props are set, and no text is present, the button shape is square rather than rectangular.
 -   `Popover`: fix limitShift logic by adding iframe offset correctly [#42950](https://github.com/WordPress/gutenberg/pull/42950)).
 
diff --git a/packages/components/src/font-size-picker/test/utils.js b/packages/components/src/font-size-picker/test/utils.js
index fc074514925cc..a640aed862387 100644
--- a/packages/components/src/font-size-picker/test/utils.js
+++ b/packages/components/src/font-size-picker/test/utils.js
@@ -116,33 +116,33 @@ describe( 'getToggleGroupOptions', () => {
 		).toEqual( [
 			{
 				key: '1',
-				value: '1',
 				label: 'S',
 				name: '1',
+				value: '1',
 			},
 			{
 				key: '2',
-				value: '2',
 				label: 'M',
 				name: '2',
+				value: '2',
 			},
 			{
 				key: '3',
-				value: '3',
 				label: 'L',
 				name: '3',
+				value: '3',
 			},
 			{
 				key: '4',
-				value: '4',
 				label: 'XL',
 				name: '4',
+				value: '4',
 			},
 			{
 				key: '5',
-				value: '5',
 				label: 'XXL',
 				name: 'XXL',
+				value: '5',
 			},
 		] );
 	} );
diff --git a/packages/components/src/font-size-picker/utils.js b/packages/components/src/font-size-picker/utils.js
index fff3d087cf3e6..dbb7882183fab 100644
--- a/packages/components/src/font-size-picker/utils.js
+++ b/packages/components/src/font-size-picker/utils.js
@@ -91,7 +91,7 @@ function getSelectOptions( optionsArray, disableCustomFontSizes ) {
 	];
 	return options.map( ( { slug, name, size } ) => ( {
 		key: slug,
-		name,
+		name: name || slug,
 		size,
 		__experimentalHint:
 			size && isSimpleCssValue( size ) && parseFloat( size ),
diff --git a/packages/edit-site/src/components/global-styles/test/typography-utils.js b/packages/edit-site/src/components/global-styles/test/typography-utils.js
index cbc0fe53a3390..2ab86fb7c8292 100644
--- a/packages/edit-site/src/components/global-styles/test/typography-utils.js
+++ b/packages/edit-site/src/components/global-styles/test/typography-utils.js
@@ -15,6 +15,14 @@ describe( 'typography utils', () => {
 					typographySettings: undefined,
 					expected: '28px',
 				},
+				// Default return non-fluid value where `size` is undefined.
+				{
+					preset: {
+						size: undefined,
+					},
+					typographySettings: undefined,
+					expected: undefined,
+				},
 				// Should return non-fluid value when fluid is `false`.
 				{
 					preset: {
@@ -26,6 +34,41 @@ describe( 'typography utils', () => {
 					},
 					expected: '28px',
 				},
+				// Should coerce number to `px` and return fluid value.
+				{
+					preset: {
+						size: 33,
+						fluid: true,
+					},
+					typographySettings: {
+						fluid: true,
+					},
+					expected:
+						'clamp(24.75px, 1.546875rem + ((1vw - 7.68px) * 2.975), 49.5px)',
+				},
+				// Should return incoming value when already clamped.
+				{
+					preset: {
+						size: 'clamp(21px, 1.3125rem + ((1vw - 7.68px) * 2.524), 42px)',
+						fluid: false,
+					},
+					typographySettings: {
+						fluid: true,
+					},
+					expected:
+						'clamp(21px, 1.3125rem + ((1vw - 7.68px) * 2.524), 42px)',
+				},
+				// Should return incoming value with unsupported unit.
+				{
+					preset: {
+						size: '1000%',
+						fluid: false,
+					},
+					typographySettings: {
+						fluid: true,
+					},
+					expected: '1000%',
+				},
 				// Should return fluid value.
 				{
 					preset: {
diff --git a/packages/edit-site/src/components/global-styles/test/use-global-styles-output.js b/packages/edit-site/src/components/global-styles/test/use-global-styles-output.js
index 8e8686ca4eed8..48f21603ad78e 100644
--- a/packages/edit-site/src/components/global-styles/test/use-global-styles-output.js
+++ b/packages/edit-site/src/components/global-styles/test/use-global-styles-output.js
@@ -711,10 +711,11 @@ describe( 'global styles renderer', () => {
 			},
 			typography: {
 				fontFamily: 'sans-serif',
+				fontSize: '14px',
 			},
 		};
 
-		it( 'Should output padding variables and other properties if useRootPaddingAwareAlignments is enabled', () => {
+		it( 'should output padding variables and other properties if useRootPaddingAwareAlignments is enabled', () => {
 			expect(
 				getStylesDeclarations( blockStyles, 'body', true )
 			).toEqual( [
@@ -724,10 +725,11 @@ describe( 'global styles renderer', () => {
 				'--wp--style--root--padding-left: 33px',
 				'background-color: var(--wp--preset--color--light-green-cyan)',
 				'font-family: sans-serif',
+				'font-size: 14px',
 			] );
 		} );
 
-		it( 'Should output padding and other properties if useRootPaddingAwareAlignments is disabled', () => {
+		it( 'should output padding and other properties if useRootPaddingAwareAlignments is disabled', () => {
 			expect(
 				getStylesDeclarations( blockStyles, 'body', false )
 			).toEqual( [
@@ -737,10 +739,11 @@ describe( 'global styles renderer', () => {
 				'padding-bottom: 33px',
 				'padding-left: 33px',
 				'font-family: sans-serif',
+				'font-size: 14px',
 			] );
 		} );
 
-		it( 'Should not output padding variables if selector is not root', () => {
+		it( 'should not output padding variables if selector is not root', () => {
 			expect(
 				getStylesDeclarations(
 					blockStyles,
@@ -754,6 +757,57 @@ describe( 'global styles renderer', () => {
 				'padding-bottom: 33px',
 				'padding-left: 33px',
 				'font-family: sans-serif',
+				'font-size: 14px',
+			] );
+		} );
+
+		it( 'should output clamp values for font-size when fluid typography is enabled', () => {
+			expect(
+				getStylesDeclarations(
+					blockStyles,
+					'.wp-block-site-title',
+					true,
+					{
+						settings: {
+							typography: {
+								fluid: true,
+							},
+						},
+					}
+				)
+			).toEqual( [
+				'background-color: var(--wp--preset--color--light-green-cyan)',
+				'padding-top: 33px',
+				'padding-right: 33px',
+				'padding-bottom: 33px',
+				'padding-left: 33px',
+				'font-family: sans-serif',
+				'font-size: clamp(10.5px, 0.65625rem + ((1vw - 7.68px) * 1.262), 21px)',
+			] );
+		} );
+
+		it( 'should output direct values for font-size when fluid typography is disabled', () => {
+			expect(
+				getStylesDeclarations(
+					blockStyles,
+					'.wp-block-site-title',
+					true,
+					{
+						settings: {
+							typography: {
+								fluid: false,
+							},
+						},
+					}
+				)
+			).toEqual( [
+				'background-color: var(--wp--preset--color--light-green-cyan)',
+				'padding-top: 33px',
+				'padding-right: 33px',
+				'padding-bottom: 33px',
+				'padding-left: 33px',
+				'font-family: sans-serif',
+				'font-size: 14px',
 			] );
 		} );
 	} );
diff --git a/packages/edit-site/src/components/global-styles/typography-panel.js b/packages/edit-site/src/components/global-styles/typography-panel.js
index f4c77abf0fd71..86a929fe4998b 100644
--- a/packages/edit-site/src/components/global-styles/typography-panel.js
+++ b/packages/edit-site/src/components/global-styles/typography-panel.js
@@ -21,6 +21,7 @@ import { useState } from '@wordpress/element';
  * Internal dependencies
  */
 import { getSupportedGlobalStylesPanels, useSetting, useStyle } from './hooks';
+import { getTypographyFontSizeValue } from './typography-utils';
 
 export function useHasTypographyPanel( name ) {
 	const hasLineHeight = useHasLineHeightControl( name );
@@ -87,7 +88,19 @@ export default function TypographyPanel( { name, element } ) {
 	} else if ( element && element !== 'text' ) {
 		prefix = `elements.${ element }.`;
 	}
+	const [ fluidTypography ] = useSetting( 'typography.fluid', name );
 	const [ fontSizes ] = useSetting( 'typography.fontSizes', name );
+
+	// Convert static font size values to fluid font sizes if fluidTypography is activated.
+	const fontSizesWithFluidValues = fontSizes.map( ( font ) => {
+		if ( !! fluidTypography ) {
+			font.size = getTypographyFontSizeValue( font, {
+				fluid: fluidTypography,
+			} );
+		}
+		return font;
+	} );
+
 	const disableCustomFontSizes = ! useSetting(
 		'typography.customFontSize',
 		name
@@ -180,7 +193,7 @@ export default function TypographyPanel( { name, element } ) {
 						>
 							<ToggleGroupControlOption
 								value="heading"
-								/* translators: 'All' refers to selecting all heading levels 
+								/* translators: 'All' refers to selecting all heading levels
 							and applying the same style to h1-h6. */
 								label={ __( 'All' ) }
 							/>
@@ -227,7 +240,7 @@ export default function TypographyPanel( { name, element } ) {
 						<FontSizePicker
 							value={ fontSize }
 							onChange={ setFontSize }
-							fontSizes={ fontSizes }
+							fontSizes={ fontSizesWithFluidValues }
 							disableCustomFontSizes={ disableCustomFontSizes }
 							size="__unstable-large"
 							__nextHasNoMarginBottom
diff --git a/packages/edit-site/src/components/global-styles/typography-utils.js b/packages/edit-site/src/components/global-styles/typography-utils.js
index 464021dfa0b9f..0c2d3a29ef5bb 100644
--- a/packages/edit-site/src/components/global-styles/typography-utils.js
+++ b/packages/edit-site/src/components/global-styles/typography-utils.js
@@ -4,19 +4,27 @@
  * ---------------------------------------------------------------
  */
 
+/**
+ * @typedef {Object} FluidPreset
+ * @property {string|undefined} max A maximum font size value.
+ * @property {string|undefined} min A minimum font size value.
+ */
+
+/**
+ * @typedef {Object} Preset
+ * @property {string}                        size  A default font size.
+ * @property {string}                        name  A font size name, displayed in the UI.
+ * @property {string}                        slug  A font size slug
+ * @property {boolean|FluidPreset|undefined} fluid A font size slug
+ */
+
 /**
  * Returns a font-size value based on a given font-size preset.
  * Takes into account fluid typography parameters and attempts to return a css formula depending on available, valid values.
  *
- * @param {Object}           preset
- * @param {string}           preset.size              A default font size.
- * @param {string}           preset.name              A font size name, displayed in the UI.
- * @param {string}           preset.slug              A font size slug.
- * @param {Object}           preset.fluid
- * @param {string|undefined} preset.fluid.max         A maximum font size value.
- * @param {string|undefined} preset.fluid.min         A minimum font size value.
- * @param {Object}           typographySettings
- * @param {boolean}          typographySettings.fluid Whether fluid typography is enabled.
+ * @param {Preset}  preset
+ * @param {Object}  typographySettings
+ * @param {boolean} typographySettings.fluid Whether fluid typography is enabled.
  *
  * @return {string} An font-size value
  */
diff --git a/packages/edit-site/src/components/global-styles/use-global-styles-output.js b/packages/edit-site/src/components/global-styles/use-global-styles-output.js
index 1e9ed77736e07..63306f050061a 100644
--- a/packages/edit-site/src/components/global-styles/use-global-styles-output.js
+++ b/packages/edit-site/src/components/global-styles/use-global-styles-output.js
@@ -24,6 +24,7 @@ import {
  * Internal dependencies
  */
 import { PRESET_METADATA, ROOT_BLOCK_SELECTOR, scopeSelector } from './utils';
+import { getTypographyFontSizeValue } from './typography-utils';
 import { GlobalStylesContext } from './context';
 import { useSetting } from './hooks';
 
@@ -276,6 +277,21 @@ export function getStylesDeclarations(
 			}
 		}
 
+		// Calculate fluid typography rules where available.
+		if ( cssProperty === 'font-size' ) {
+			/*
+			 * getTypographyFontSizeValue() will check
+			 * if fluid typography has been activated and also
+			 * whether the incoming value can be converted to a fluid value.
+			 * Values that already have a "clamp()" function will not pass the test,
+			 * and therefore the original $value will be returned.
+			 */
+			ruleValue = getTypographyFontSizeValue(
+				{ size: ruleValue },
+				tree?.settings?.typography
+			);
+		}
+
 		output.push( `${ cssProperty }: ${ ruleValue }` );
 	} );