diff --git a/docs/reference-guides/theme-json-reference/theme-json-living.md b/docs/reference-guides/theme-json-reference/theme-json-living.md
index c58b8b3239f33e..754d0c50caac83 100644
--- a/docs/reference-guides/theme-json-reference/theme-json-living.md
+++ b/docs/reference-guides/theme-json-reference/theme-json-living.md
@@ -107,6 +107,7 @@ Settings related to background.
 | Property  | Type   | Default | Props  |
 | ---       | ---    | ---    |---   |
 | backgroundImage | boolean | false |  |
+| backgroundSize | boolean | false |  |
 
 ---
 
diff --git a/schemas/json/block.json b/schemas/json/block.json
index 299327a96a64b8..0d3fca0b8fd61b 100644
--- a/schemas/json/block.json
+++ b/schemas/json/block.json
@@ -341,6 +341,22 @@
 						}
 					}
 				},
+				"background": {
+					"type": "object",
+					"description": "This value signals that a block supports some of the CSS style properties related to background. When it does, the block editor will show UI controls for the user to set their values if the theme declares support.\n\nWhen the block declares support for a specific background property, its attributes definition is extended to include the style attribute.",
+					"properties": {
+						"backgroundImage": {
+							"type": "boolean",
+							"description": "Allow blocks to define a background image.",
+							"default": false
+						},
+						"backgroundSize": {
+							"type": "boolean",
+							"description": "Allow blocks to define values related to the size of a background image, including size, position, and repeat controls",
+							"default": false
+						}
+					}
+				},
 				"html": {
 					"type": "boolean",
 					"description": "By default, a block’s markup can be edited individually. To disable this behavior, set html to false.",
diff --git a/schemas/json/theme.json b/schemas/json/theme.json
index 8ec1de58478b8d..982b503b4b9cf7 100644
--- a/schemas/json/theme.json
+++ b/schemas/json/theme.json
@@ -258,6 +258,11 @@
 							"description": "Allow users to set a background image.",
 							"type": "boolean",
 							"default": false
+						},
+						"backgroundSize": {
+							"description": "Allow users to set values related to the size of a background image, including size, position, and repeat controls.",
+							"type": "boolean",
+							"default": false
 						}
 					},
 					"additionalProperties": false