diff --git a/packages/block-library/src/avatar/user-control.js b/packages/block-library/src/avatar/user-control.js
index 49370b39716eff..598c05011eaed7 100644
--- a/packages/block-library/src/avatar/user-control.js
+++ b/packages/block-library/src/avatar/user-control.js
@@ -33,6 +33,7 @@ function UserControl( { value, onChange } ) {
 
 	return (
 		<ComboboxControl
+			__nextHasNoMarginBottom
 			label={ __( 'User' ) }
 			help={ __(
 				'Select the avatar user to display, if it is blank it will use the post/page author.'
diff --git a/packages/block-library/src/post-author/edit.js b/packages/block-library/src/post-author/edit.js
index be92912e41db8a..b0a2fb2883f79a 100644
--- a/packages/block-library/src/post-author/edit.js
+++ b/packages/block-library/src/post-author/edit.js
@@ -103,6 +103,7 @@ function PostAuthorEdit( {
 						authorOptions.length &&
 						( ( showCombobox && (
 							<ComboboxControl
+								__nextHasNoMarginBottom
 								label={ __( 'Author' ) }
 								options={ authorOptions }
 								value={ authorId }
diff --git a/packages/editor/src/components/page-attributes/parent.js b/packages/editor/src/components/page-attributes/parent.js
index 339ef64285931a..4ee2491e17209b 100644
--- a/packages/editor/src/components/page-attributes/parent.js
+++ b/packages/editor/src/components/page-attributes/parent.js
@@ -158,6 +158,7 @@ export function PageAttributesParent() {
 
 	return (
 		<ComboboxControl
+			__nextHasNoMarginBottom
 			className="editor-page-attributes__parent"
 			label={ parentPageLabel }
 			value={ parentPostId }
diff --git a/packages/editor/src/components/post-author/combobox.js b/packages/editor/src/components/post-author/combobox.js
index c0ffdbbb26a0dc..422d5a4ba4f4b6 100644
--- a/packages/editor/src/components/post-author/combobox.js
+++ b/packages/editor/src/components/post-author/combobox.js
@@ -95,6 +95,7 @@ function PostAuthorCombobox() {
 
 	return (
 		<ComboboxControl
+			__nextHasNoMarginBottom
 			label={ __( 'Author' ) }
 			options={ authorOptions }
 			value={ authorId }