diff --git a/lib/class-wp-theme-json-gutenberg.php b/lib/class-wp-theme-json-gutenberg.php
index 2e372fc32c1702..7313afeba91bca 100644
--- a/lib/class-wp-theme-json-gutenberg.php
+++ b/lib/class-wp-theme-json-gutenberg.php
@@ -3646,4 +3646,78 @@ private static function resolve_custom_css_format( $tree ) {
 
 		return $tree;
 	}
+
+	/**
+	 * Replaces CSS variables with their values in place.
+	 *
+	 * @since 6.3.0
+	 * @param array $styles CSS declarations to convert.
+	 * @param array $values key => value pairs to use for replacement.
+	 * @return array
+	 */
+	private static function convert_variables_to_value( $styles, $values ) {
+		foreach ( $styles as $key => $style ) {
+			if ( is_array( $style ) ) {
+				$styles[ $key ] = self::convert_variables_to_value( $style, $values );
+				continue;
+			}
+
+			if ( 0 <= strpos( $style, 'var(' ) ) {
+				// find all the variables in the string in the form of var(--variable-name, fallback), with fallback in the second capture group.
+
+				$has_matches = preg_match_all( '/var\(([^),]+)?,?\s?(\S+)?\)/', $style, $var_parts );
+
+				if ( $has_matches ) {
+					$resolved_style = $styles[ $key ];
+					foreach ( $var_parts[1] as $index => $var_part ) {
+						$key_in_values   = 'var(' . $var_part . ')';
+						$rule_to_replace = $var_parts[0][ $index ]; // the css rule to replace e.g. var(--wp--preset--color--vivid-green-cyan).
+						$fallback        = $var_parts[2][ $index ]; // the fallback value.
+						$resolved_style  = str_replace(
+							array(
+								$rule_to_replace,
+								$fallback,
+							),
+							array(
+								isset( $values[ $key_in_values ] ) ? $values[ $key_in_values ] : $rule_to_replace,
+								isset( $values[ $fallback ] ) ? $values[ $fallback ] : $fallback,
+							),
+							$resolved_style
+						);
+					}
+					$styles[ $key ] = $resolved_style;
+				}
+			}
+		}
+
+		return $styles;
+	}
+
+	/**
+	 * Resolves the values of CSS variables in the given styles.
+	 *
+	 * @since 6.3.0
+	 * @param WP_Theme_JSON_Gutenberg $theme_json The theme json resolver.
+	 *
+	 * @return WP_Theme_JSON_Gutenberg The $theme_json with resolved variables.
+	 */
+	public static function resolve_variables( $theme_json ) {
+		$settings    = $theme_json->get_settings();
+		$styles      = $theme_json->get_raw_data()['styles'];
+		$preset_vars = static::compute_preset_vars( $settings, static::VALID_ORIGINS );
+		$theme_vars  = static::compute_theme_vars( $settings );
+		$vars        = array_reduce(
+			array_merge( $preset_vars, $theme_vars ),
+			function( $carry, $item ) {
+				$name                    = $item['name'];
+				$carry[ "var({$name})" ] = $item['value'];
+				return  $carry;
+			},
+			array()
+		);
+
+		$theme_json->theme_json['styles'] = self::convert_variables_to_value( $styles, $vars );
+		return $theme_json;
+	}
+
 }
diff --git a/lib/global-styles-and-settings.php b/lib/global-styles-and-settings.php
index 309f01ca2bdd31..35ff4e13d61a75 100644
--- a/lib/global-styles-and-settings.php
+++ b/lib/global-styles-and-settings.php
@@ -238,6 +238,8 @@ function _gutenberg_clean_theme_json_caches() {
  * @since 5.9.0
  * @since 6.3.0 the internal link format "var:preset|color|secondary" is resolved
  * to "var(--wp--preset--font-size--small)" so consumers don't have to.
+ * @since 6.3.0 `transforms` is now usable in the `context` parameter. In case [`transforms`]['resolve_variables']
+ * is defined, variables are resolved to their value in the styles.
  *
  * @param array $path    Path to the specific style to retrieve. Optional.
  *                       If empty, will return all styles.
@@ -249,6 +251,9 @@ function _gutenberg_clean_theme_json_caches() {
  *     @type string $origin     Which origin to take data from.
  *                              Valid values are 'all' (core, theme, and user) or 'base' (core and theme).
  *                              If empty or unknown, 'all' is used.
+ *     @type array $transforms Which transformation(s) to apply.
+ *                              Valid value is array( 'resolve-variables' ).
+ *                              If defined, variables are resolved to their value in the styles.
  * }
  * @return array The styles to retrieve.
  */
@@ -261,8 +266,16 @@ function gutenberg_get_global_styles( $path = array(), $context = array() ) {
 	if ( isset( $context['origin'] ) && 'base' === $context['origin'] ) {
 		$origin = 'theme';
 	}
-	$styles = WP_Theme_JSON_Resolver_Gutenberg::get_merged_data( $origin )->get_raw_data()['styles'];
 
+	$resolve_variables = isset( $context['transforms'] )
+	&& is_array( $context['transforms'] )
+	&& in_array( 'resolve-variables', $context['transforms'], true );
+
+	$merged_data = WP_Theme_JSON_Resolver_Gutenberg::get_merged_data( $origin );
+	if ( $resolve_variables ) {
+		$merged_data = WP_Theme_JSON_Gutenberg::resolve_variables( $merged_data );
+	}
+	$styles = $merged_data->get_raw_data()['styles'];
 	return _wp_array_get( $styles, $path, $styles );
 }
 
diff --git a/phpunit/class-wp-theme-json-test.php b/phpunit/class-wp-theme-json-test.php
index 1e5147bd0ed632..bd1d578a1297b6 100644
--- a/phpunit/class-wp-theme-json-test.php
+++ b/phpunit/class-wp-theme-json-test.php
@@ -2021,4 +2021,158 @@ public function test_internal_syntax_is_converted_to_css_variables() {
 		$this->assertEquals( 'var(--wp--preset--color--s)', $styles['blocks']['core/quote']['variations']['plain']['color']['background'], 'Style variations: Assert the internal variables are convert to CSS custom variables.' );
 
 	}
+
+	public function test_resolve_variables() {
+		$primary_color   = '#9DFF20';
+		$secondary_color = '#9DFF21';
+		$contrast_color  = '#000';
+		$raw_color_value = '#efefef';
+		$large_font      = '18px';
+		$small_font      = '12px';
+		$theme_json      = new WP_Theme_JSON_Gutenberg(
+			array(
+				'version'  => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
+				'settings' => array(
+					'color'      => array(
+						'palette' => array(
+							'theme' => array(
+								array(
+									'color' => $primary_color,
+									'name'  => 'Primary',
+									'slug'  => 'primary',
+								),
+								array(
+									'color' => $secondary_color,
+									'name'  => 'Secondary',
+									'slug'  => 'secondary',
+								),
+								array(
+									'color' => $contrast_color,
+									'name'  => 'Contrast',
+									'slug'  => 'contrast',
+								),
+							),
+						),
+					),
+					'typography' => array(
+						'fontSizes' => array(
+							array(
+								'size' => $small_font,
+								'name' => 'Font size small',
+								'slug' => 'small',
+							),
+							array(
+								'size' => $large_font,
+								'name' => 'Font size large',
+								'slug' => 'large',
+							),
+						),
+					),
+				),
+				'styles'   => array(
+					'color'    => array(
+						'background' => 'var(--wp--preset--color--primary)',
+						'text'       => $raw_color_value,
+					),
+					'elements' => array(
+						'button' => array(
+							'color'      => array(
+								'text' => 'var(--wp--preset--color--contrast)',
+							),
+							'typography' => array(
+								'fontSize' => 'var(--wp--preset--font-size--small)',
+							),
+						),
+					),
+					'blocks'   => array(
+						'core/post-terms'      => array(
+							'typography' => array( 'fontSize' => 'var(--wp--preset--font-size--small)' ),
+							'color'      => array( 'background' => $raw_color_value ),
+						),
+						'core/more'            => array(
+							'typography' => array( 'fontSize' => 'var(--undefined--font-size--small)' ),
+							'color'      => array( 'background' => 'linear-gradient(90deg, var(--wp--preset--color--primary) 0%, var(--wp--preset--color--secondary) 35%, var(--wp--undefined--color--secondary) 100%)' ),
+						),
+						'core/comment-content' => array(
+							'typography' => array( 'fontSize' => 'calc(var(--wp--preset--font-size--small, 12px) + 20px)' ),
+							'color'      => array(
+								'text'       => 'var(--wp--preset--color--primary, red)',
+								'background' => 'var(--wp--preset--color--primary, var(--wp--preset--font-size--secondary))',
+								'link'       => 'var(--undefined--color--primary, var(--wp--preset--font-size--secondary))',
+							),
+						),
+						'core/comments'        => array(
+							'color' => array(
+								'text'       => 'var(--undefined--color--primary, var(--wp--preset--font-size--small))',
+								'background' => 'var(--wp--preset--color--primary, var(--undefined--color--primary))',
+							),
+						),
+						'core/navigation'      => array(
+							'elements' => array(
+								'link' => array(
+									'color'      => array(
+										'background' => 'var(--wp--preset--color--primary)',
+										'text'       => 'var(--wp--preset--color--secondary)',
+									),
+									'typography' => array(
+										'fontSize' => 'var(--wp--preset--font-size--large)',
+									),
+								),
+							),
+						),
+						'core/quote'           => array(
+							'typography' => array( 'fontSize' => 'var(--wp--preset--font-size--large)' ),
+							'color'      => array( 'background' => 'var(--wp--preset--color--primary)' ),
+							'variations' => array(
+								'plain' => array(
+									'typography' => array( 'fontSize' => 'var(--wp--preset--font-size--small)' ),
+									'color'      => array( 'background' => 'var(--wp--preset--color--secondary)' ),
+								),
+							),
+						),
+					),
+				),
+			)
+		);
+
+		$styles = $theme_json::resolve_variables( $theme_json )->get_raw_data()['styles'];
+
+		$this->assertEquals( $primary_color, $styles['color']['background'], 'Top level: Assert values are converted' );
+		$this->assertEquals( $raw_color_value, $styles['color']['text'], 'Top level: Assert raw values stay intact' );
+
+		$this->assertEquals( $contrast_color, $styles['elements']['button']['color']['text'], 'Elements: color' );
+		$this->assertEquals( $small_font, $styles['elements']['button']['typography']['fontSize'], 'Elements: font-size' );
+
+		$this->assertEquals( $large_font, $styles['blocks']['core/quote']['typography']['fontSize'], 'Blocks: font-size' );
+		$this->assertEquals( $primary_color, $styles['blocks']['core/quote']['color']['background'], 'Blocks: color' );
+		$this->assertEquals( $raw_color_value, $styles['blocks']['core/post-terms']['color']['background'], 'Blocks: Raw color value stays intact' );
+		$this->assertEquals( $small_font, $styles['blocks']['core/post-terms']['typography']['fontSize'], 'Block core/post-terms: font-size' );
+		$this->assertEquals(
+			"linear-gradient(90deg, $primary_color 0%, $secondary_color 35%, var(--wp--undefined--color--secondary) 100%)",
+			$styles['blocks']['core/more']['color']['background'],
+			'Blocks: multiple colors and undefined color'
+		);
+		$this->assertEquals( 'var(--undefined--font-size--small)', $styles['blocks']['core/more']['typography']['fontSize'], 'Blocks: undefined font-size ' );
+		$this->assertEquals( "calc($small_font + 20px)", $styles['blocks']['core/comment-content']['typography']['fontSize'], 'Blocks: font-size in random place' );
+		$this->assertEquals( $primary_color, $styles['blocks']['core/comment-content']['color']['text'], 'Blocks: text color with fallback' );
+		$this->assertEquals( $primary_color, $styles['blocks']['core/comment-content']['color']['background'], 'Blocks: background color with var as fallback' );
+		$this->assertEquals( $primary_color, $styles['blocks']['core/navigation']['elements']['link']['color']['background'], 'Block element: background color' );
+		$this->assertEquals( $secondary_color, $styles['blocks']['core/navigation']['elements']['link']['color']['text'], 'Block element: text color' );
+		$this->assertEquals( $large_font, $styles['blocks']['core/navigation']['elements']['link']['typography']['fontSize'], 'Block element: font-size' );
+
+		$this->assertEquals(
+			"var(--undefined--color--primary, $small_font)",
+			$styles['blocks']['core/comments']['color']['text'],
+			'Blocks: text color with undefined var and fallback'
+		);
+		$this->assertEquals(
+			$primary_color,
+			$styles['blocks']['core/comments']['color']['background'],
+			'Blocks: background color with variable and undefined fallback'
+		);
+
+		$this->assertEquals( $small_font, $styles['blocks']['core/quote']['variations']['plain']['typography']['fontSize'], 'Block variations: font-size' );
+		$this->assertEquals( $secondary_color, $styles['blocks']['core/quote']['variations']['plain']['color']['background'], 'Block variations: color' );
+	}
+
 }