diff --git a/src/wp-admin/css/common.css b/src/wp-admin/css/common.css
index 529970bd93..8f81235b05 100644
--- a/src/wp-admin/css/common.css
+++ b/src/wp-admin/css/common.css
@@ -3368,7 +3368,8 @@ img {
 .control-section.open .accordion-section-title:after,
 #customize-info.open .accordion-section-title:after,
 .nav-menus-php .menu-item-edit-active .item-edit:before,
-.widget.open .widget-top .widget-action .toggle-indicator:before {
+.widget.open .widget-top .widget-action .toggle-indicator:before,
+.widget.widget-in-question .widget-top .widget-action .toggle-indicator:before  {
 	content: "\f142";
 }
 
diff --git a/src/wp-admin/css/widgets.css b/src/wp-admin/css/widgets.css
index 8cdd87f5a8..ede470953a 100644
--- a/src/wp-admin/css/widgets.css
+++ b/src/wp-admin/css/widgets.css
@@ -381,10 +381,6 @@ div#widgets-left .widget-holder {
 	box-shadow: none;
 }
 
-#available-widgets .widget-action {
-	display: none;
-}
-
 #available-widgets .widget {
 	margin: 0;
 }
@@ -516,8 +512,11 @@ div#widgets-right .closed .widgets-sortables {
 }
 
 #available-widgets .widget-control-edit .edit,
+#available-widgets .widget-action .edit,
 #widgets-left .inactive-sidebar .widget-control-edit .add,
-#widgets-right .widget-control-edit .add {
+#widgets-left .inactive-sidebar .widget-action .add,
+#widgets-right .widget-control-edit .add,
+#widgets-right .widget-action .add {
 	display: none;
 }
 
@@ -664,44 +663,40 @@ div#widgets-right .widget-top:hover,
 }
 
 .widgets-chooser li {
-	padding: 10px 15px 10px 35px;
 	border-bottom: 1px solid #ccc;
 	background: #fff;
 	margin: 0;
-	cursor: pointer;
-	outline: none;
 	position: relative;
+}
+
+.widgets-chooser .widgets-chooser-button {
+	width: 100%;
+	padding: 10px 15px 10px 35px;
+	background: transparent;
+	border: 0;
+	box-sizing: border-box;
+	text-align: left;
+	cursor: pointer;
 	transition: background 0.2s ease-in-out;
 }
 
- /* @todo looks like these hover/focus states are overridden by .widgets-chooser-selected */
-.widgets-chooser li:hover,
-.widgets-chooser li:focus {
-	background: rgba(255,255,255,0.7);
-}
-
-.widgets-chooser li:focus:before {
-	content: "\f147";
-	display: block;
-	-webkit-font-smoothing: antialiased;
-	font: normal 26px/1 dashicons;
-	color: #555d66;
-	position: absolute;
-	top: 7px;
-	left: 5px;
+/* @todo looks like these hover/focus states are overridden by .widgets-chooser-selected */
+.widgets-chooser .widgets-chooser-button:hover,
+.widgets-chooser .widgets-chooser-button:focus {
+	outline: none;
+	text-decoration: underline;
 }
 
 .widgets-chooser li:last-child {
 	border: none;
 }
 
-.widgets-chooser li.widgets-chooser-selected {
-	background: #00a0d2;
+.widgets-chooser .widgets-chooser-selected .widgets-chooser-button {
+	background: #0073aa;
 	color: #fff;
 }
 
-.widgets-chooser li.widgets-chooser-selected:before,
-.widgets-chooser li.widgets-chooser-selected:focus:before {
+.widgets-chooser .widgets-chooser-selected:before {
 	content: "\f147";
 	display: block;
 	-webkit-font-smoothing: antialiased;
@@ -717,10 +712,6 @@ div#widgets-right .widget-top:hover,
 	text-align: center;
 }
 
-.widgets-chooser button {
-	margin-right: 5px;
-}
-
 #available-widgets .widget .widget-top {
 	cursor: pointer;
 }
diff --git a/src/wp-admin/includes/widgets.php b/src/wp-admin/includes/widgets.php
index 0cf647c3f4..640e00afe4 100644
--- a/src/wp-admin/includes/widgets.php
+++ b/src/wp-admin/includes/widgets.php
@@ -90,8 +90,13 @@ function wp_list_widget_controls( $sidebar, $sidebar_name = '' ) {
 	echo '<div id="' . esc_attr( $sidebar ) . '" class="widgets-sortables">';
 
 	if ( $sidebar_name ) {
+		$add_to = sprintf(
+			/* translators: %s: widgets sidebar name. */
+			__( 'Add to: %s' ),
+			$sidebar_name
+		);
 		?>
-		<div class="sidebar-name">
+		<div class="sidebar-name" data-add-to="<?php echo esc_attr( $add_to ); ?>">
 			<button type="button" class="handlediv hide-if-no-js" aria-expanded="true">
 				<span class="screen-reader-text"><?php echo esc_html( $sidebar_name ); ?></span>
 				<span class="toggle-indicator" aria-hidden="true"></span>
@@ -239,7 +244,8 @@ function wp_widget_control( $sidebar_args ) {
 	<div class="widget-top">
 	<div class="widget-title-action">
 		<button type="button" class="widget-action hide-if-no-js" aria-expanded="false">
-			<span class="screen-reader-text"><?php printf( __( 'Edit widget: %s' ), $widget_title ); ?></span>
+			<span class="screen-reader-text edit"><?php printf( __( 'Edit widget: %s' ), $widget_title ); ?></span>
+			<span class="screen-reader-text add"><?php printf( __( 'Add widget: %s' ), $widget_title ); ?></span>
 			<span class="toggle-indicator" aria-hidden="true"></span>
 		</button>
 		<a class="widget-control-edit hide-if-js" href="<?php echo esc_url( add_query_arg( $query_arg ) ); ?>">
diff --git a/src/wp-admin/js/widgets.js b/src/wp-admin/js/widgets.js
index bbd287d984..59c2b71dfb 100644
--- a/src/wp-admin/js/widgets.js
+++ b/src/wp-admin/js/widgets.js
@@ -21,7 +21,8 @@ wpWidgets = {
 	l10n: {
 		save: '{save}',
 		saved: '{saved}',
-		saveAlert: '{saveAlert}'
+		saveAlert: '{saveAlert}',
+		widgetAdded: '{widgetAdded}'
 	},
 
 	/**
@@ -176,19 +177,16 @@ wpWidgets = {
 						widget.removeClass( 'open' );
 					});
 				}
-				e.preventDefault();
 			} else if ( target.hasClass('widget-control-save') ) {
 				wpWidgets.save( target.closest('div.widget'), 0, 1, 0 );
 				e.preventDefault();
 			} else if ( target.hasClass('widget-control-remove') ) {
 				wpWidgets.save( target.closest('div.widget'), 1, 1, 0 );
-				e.preventDefault();
 			} else if ( target.hasClass('widget-control-close') ) {
 				widget = target.closest('div.widget');
 				widget.removeClass( 'open' );
 				toggleBtn.attr( 'aria-expanded', 'false' );
 				wpWidgets.close( widget );
-				e.preventDefault();
 			} else if ( target.attr( 'id' ) === 'inactive-widgets-control-remove' ) {
 				wpWidgets.removeInactiveWidgets();
 				e.preventDefault();
@@ -433,35 +431,53 @@ wpWidgets = {
 		$( '#widgets-right .widgets-holder-wrap' ).each( function( index, element ) {
 			var $element = $( element ),
 				name = $element.find( '.sidebar-name h2' ).text(),
+				ariaLabel = $element.find( '.sidebar-name' ).data( 'add-to' ),
 				id = $element.find( '.widgets-sortables' ).attr( 'id' ),
-				li = $('<li tabindex="0">').text( $.trim( name ) );
+				li = $( '<li>' ),
+				button = $( '<button>', {
+					type: 'button',
+					'aria-pressed': 'false',
+					'class': 'widgets-chooser-button',
+					'aria-label': ariaLabel
+				} ).text( $.trim( name ) );
+
+			li.append( button );
 
 			if ( index === 0 ) {
 				li.addClass( 'widgets-chooser-selected' );
+				button.attr( 'aria-pressed', 'true' );
 			}
 
 			selectSidebar.append( li );
 			li.data( 'sidebarId', id );
 		});
 
-		$( '#available-widgets .widget .widget-title' ).on( 'click.widgets-chooser', function() {
-			var $widget = $(this).closest( '.widget' );
+		$( '#available-widgets .widget .widget-top' ).on( 'click.widgets-chooser', function() {
+			var $widget = $( this ).closest( '.widget' ),
+				toggleButton = $( this ).find( '.widget-action' ),
+				chooserButtons = selectSidebar.find( '.widgets-chooser-button' );
 
 			if ( $widget.hasClass( 'widget-in-question' ) || $( '#widgets-left' ).hasClass( 'chooser' ) ) {
+				toggleButton.attr( 'aria-expanded', 'false' );
 				self.closeChooser();
 			} else {
 				// Open the chooser
 				self.clearWidgetSelection();
 				$( '#widgets-left' ).addClass( 'chooser' );
+				// Add CSS class and insert the chooser after the widget description.
 				$widget.addClass( 'widget-in-question' ).children( '.widget-description' ).after( chooser );
-
+				// Open the chooser with a slide down animation.
 				chooser.slideDown( 300, function() {
-					selectSidebar.find('.widgets-chooser-selected').focus();
+					// Update the toggle button aria-expanded attribute after previous DOM manipulations.
+					toggleButton.attr( 'aria-expanded', 'true' );
 				});
 
-				selectSidebar.find( 'li' ).on( 'focusin.widgets-chooser', function() {
-					selectSidebar.find('.widgets-chooser-selected').removeClass( 'widgets-chooser-selected' );
-					$(this).addClass( 'widgets-chooser-selected' );
+				chooserButtons.on( 'click.widgets-chooser', function() {
+					selectSidebar.find( '.widgets-chooser-selected' ).removeClass( 'widgets-chooser-selected' );
+					chooserButtons.attr( 'aria-pressed', 'false' );
+					$( this )
+						.attr( 'aria-pressed', 'true' )
+						.closest( 'li' ).addClass( 'widgets-chooser-selected' );
 				} );
 			}
 		});
@@ -477,15 +493,7 @@ wpWidgets = {
 				self.closeChooser();
 			}
 		}).on( 'keyup.widgets-chooser', function( event ) {
-			if ( event.which === $.ui.keyCode.ENTER ) {
-				if ( $( event.target ).hasClass( 'widgets-chooser-cancel' ) ) {
-					// Close instead of adding when pressing Enter on the Cancel button
-					self.closeChooser();
-				} else {
-					self.addWidget( chooser );
-					self.closeChooser();
-				}
-			} else if ( event.which === $.ui.keyCode.ESCAPE ) {
+			if ( event.which === $.ui.keyCode.ESCAPE ) {
 				self.closeChooser();
 			}
 		});
@@ -705,15 +713,20 @@ wpWidgets = {
 			// Cannot use a callback in the animation above as it fires twice,
 			// have to queue this "by hand".
 			widget.find( '.widget-title' ).trigger('click');
+			// At the end of the animation, announce the widget has been added.
+			window.wp.a11y.speak( wpWidgets.l10n.widgetAdded, 'assertive' );
 		}, 250 );
 	},
 
 	closeChooser: function() {
-		var self = this;
+		var self = this,
+			widgetInQuestion = $( '#available-widgets .widget-in-question' );
 
 		$( '.widgets-chooser' ).slideUp( 200, function() {
 			$( '#wpbody-content' ).append( this );
 			self.clearWidgetSelection();
+			// Move focus back to the toggle button.
+			widgetInQuestion.find( '.widget-action' ).attr( 'aria-expanded', 'false' ).focus();
 		});
 	},
 
diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index 6a1a7f2bd8..45cb46348d 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -786,14 +786,15 @@ function wp_default_scripts( &$scripts ) {
 
 		$scripts->add( 'admin-gallery', "/wp-admin/js/gallery$suffix.js", array( 'jquery-ui-sortable' ) );
 
-		$scripts->add( 'admin-widgets', "/wp-admin/js/widgets$suffix.js", array( 'jquery-ui-sortable', 'jquery-ui-draggable', 'jquery-ui-droppable' ), false, 1 );
+		$scripts->add( 'admin-widgets', "/wp-admin/js/widgets$suffix.js", array( 'jquery-ui-sortable', 'jquery-ui-draggable', 'jquery-ui-droppable', 'wp-a11y' ), false, 1 );
 		did_action( 'init' ) && $scripts->add_inline_script(
 			'admin-widgets', sprintf(
 				'wpWidgets.l10n = %s;', wp_json_encode(
 					array(
-						'save'      => __( 'Save' ),
-						'saved'     => __( 'Saved' ),
-						'saveAlert' => __( 'The changes you made will be lost if you navigate away from this page.' ),
+						'save'        => __( 'Save' ),
+						'saved'       => __( 'Saved' ),
+						'saveAlert'   => __( 'The changes you made will be lost if you navigate away from this page.' ),
+						'widgetAdded' => __( 'Widget has been added to the selected sidebar' ),
 					)
 				)
 			)