diff --git a/src/wp-admin/css/customize-controls.css b/src/wp-admin/css/customize-controls.css
index 3ec8f2f9d3..eaaee146c4 100644
--- a/src/wp-admin/css/customize-controls.css
+++ b/src/wp-admin/css/customize-controls.css
@@ -1168,6 +1168,21 @@ p.customize-section-description {
 	border-left: none;
 	margin-top: 0;
 }
+#customize-theme-controls .control-section-themes .customize-section-back {
+	position: absolute;
+	right: 0;
+	top: 0;
+	height: 80px;
+	border-left: 1px solid #ddd;
+	border-right: 4px solid #fff;
+}
+#customize-theme-controls .control-section-themes .customize-section-back:before {
+	content: "\f345";
+}
+#customize-theme-controls .control-section-themes .customize-section-back:hover,
+#customize-theme-controls .control-section-themes .customize-section-back:focus {
+	border-right-color: #0073aa;
+}
 
 #customize-theme-controls .control-section-themes .customize-themes-panel .accordion-section-title:first-child:hover, /* Not a focusable element. */
 #customize-theme-controls .control-section-themes .customize-themes-panel .accordion-section-title:first-child {
diff --git a/src/wp-admin/js/customize-controls.js b/src/wp-admin/js/customize-controls.js
index af93b06ce5..518b10996d 100644
--- a/src/wp-admin/js/customize-controls.js
+++ b/src/wp-admin/js/customize-controls.js
@@ -1164,6 +1164,15 @@
 		attachEvents: function () {
 			var section = this;
 
+			// Expand/Collapse accordion sections on click.
+			section.container.find( '.customize-section-back' ).on( 'click keydown', function( event ) {
+				if ( api.utils.isKeydownButNotEnterEvent( event ) ) {
+					return;
+				}
+				event.preventDefault(); // Keep this AFTER the key filter above
+				section.collapse();
+			});
+
 			// Expand/Collapse section/panel.
 			section.container.find( '.change-theme, .customize-theme' ).on( 'click keydown', function( event ) {
 				if ( api.utils.isKeydownButNotEnterEvent( event ) ) {
diff --git a/src/wp-includes/customize/class-wp-customize-themes-section.php b/src/wp-includes/customize/class-wp-customize-themes-section.php
index 72175a836f..415ef47222 100644
--- a/src/wp-includes/customize/class-wp-customize-themes-section.php
+++ b/src/wp-includes/customize/class-wp-customize-themes-section.php
@@ -50,6 +50,7 @@ class WP_Customize_Themes_Section extends WP_Customize_Section {
 			</h3>
 			<div class="customize-themes-panel control-panel-content themes-php">
 				<h3 class="accordion-section-title customize-section-title">
+					<button class="customize-section-back" tabindex="0" type="button"><span class="screen-reader-text"><?php _e( 'Back' ); ?></span></button>
 					<span class="customize-action"><?php _e( 'Customizing' ); ?></span>
 					<?php _e( 'Themes' ); ?>
 					<span class="title-count theme-count"><?php echo count( $this->controls ) + 1 /* Active theme */; ?></span>