diff --git a/Echo.i18n.php b/Echo.i18n.php
index 28e2ea2e4..ce72ea261 100644
--- a/Echo.i18n.php
+++ b/Echo.i18n.php
@@ -143,6 +143,7 @@ $1',
 	'echo-overlay-link' => 'All notifications',
 	'echo-overlay-title' => 'Notifications',
 	'echo-overlay-title-overflow' => 'Notifications (showing $1 of $2 unread)',
+	'echo-mark-all-as-read' => 'Mark all as read',
 
 	// Special page
 	'echo-date-today' => 'Today',
@@ -440,6 +441,7 @@ The new notification count next to notification link, for example: 99+
 * $1 - the number of unread notifications being shown
 * $2 - the total number of unread notifications that exist
 {{Identical|Notification}}',
+	'echo-mark-all-as-read' => 'Text for button that marks all unread notifications as read. Keep this short as possible.',
 	'echo-date-today' => "The header text for today's notification section",
 	'echo-date-yesterday' => "The header text for yesterday's notification section",
 	'echo-date-header' => '{{optional}}
diff --git a/Echo.php b/Echo.php
index 9f012e022..a23c3628b 100644
--- a/Echo.php
+++ b/Echo.php
@@ -129,6 +129,7 @@ $wgResourceModules += array(
 			'mediawiki.jqueryMsg',
 			'jquery.badge',
 			'ext.echo.icons',
+			'mediawiki.ui',
 		),
 		'messages' => array(
 			'echo-link-new',
@@ -137,6 +138,7 @@ $wgResourceModules += array(
 			'echo-overlay-title-overflow',
 			'echo-overlay-link',
 			'echo-none',
+			'echo-mark-all-as-read',
 		),
 	),
 	'ext.echo.special' => $echoResourceTemplate + array(
diff --git a/Hooks.php b/Hooks.php
index d054b63a3..b91a880e5 100644
--- a/Hooks.php
+++ b/Hooks.php
@@ -620,7 +620,7 @@ class EchoHooks {
 	 * @return bool true in all cases
 	 */
 	public static function makeGlobalVariablesScript( &$vars, OutputPage $outputPage ) {
-		global $wgEchoShowFullNotificationsLink, $wgEchoHelpPage;
+		global $wgEchoShowFullNotificationsLink, $wgEchoHelpPage, $wgEchoMaxNotificationCount;
 		$user = $outputPage->getUser();
 
 		// Provide info for the Overlay
@@ -631,6 +631,7 @@ class EchoHooks {
 				'notifications-link-full' => $wgEchoShowFullNotificationsLink,
 				'timestamp' => $timestamp->getTimestamp( TS_UNIX ),
 				'notification-count' => EchoNotificationController::getFormattedNotificationCount( $user ),
+				'max-notification-count' => $wgEchoMaxNotificationCount,
 			);
 			$vars['wgEchoHelpPage'] = $wgEchoHelpPage;
 		}
diff --git a/api/ApiEchoNotifications.php b/api/ApiEchoNotifications.php
index 64132a2d8..45a2c918b 100644
--- a/api/ApiEchoNotifications.php
+++ b/api/ApiEchoNotifications.php
@@ -14,6 +14,8 @@ class ApiEchoNotifications extends ApiQueryBase {
 		$params = $this->extractRequestParams();
 		if ( count( $params['markread'] ) ) {
 			EchoNotificationController::markRead( $user, $params['markread'] );
+		} elseif ( $params['markallread'] ) {
+			EchoNotificationController::markAllRead( $user );
 		}
 
 		$prop = $params['prop'];
@@ -161,6 +163,10 @@ class ApiEchoNotifications extends ApiQueryBase {
 			'markread' => array(
 				ApiBase::PARAM_ISMULTI => true,
 			),
+			'markallread' => array(
+				ApiBase::PARAM_REQUIRED => false,
+				ApiBase::PARAM_TYPE => 'boolean'
+			),
 			'format' => array(
 				ApiBase::PARAM_TYPE => array(
 					'text',
@@ -188,6 +194,7 @@ class ApiEchoNotifications extends ApiQueryBase {
 		return array(
 			'prop' => 'Details to request.',
 			'markread' => 'A list of notification IDs to mark as read',
+			'markallread' => "If set to true, marks all of a user's notifications as read",
 			'format' => 'If specified, notifications will be returned formatted this way.',
 			'index' => 'If specified, a list of notification IDs, in order, will be returned.',
 			'limit' => 'The maximum number of notifications to return.',
diff --git a/controller/NotificationController.php b/controller/NotificationController.php
index 481768e49..e9ce8553d 100644
--- a/controller/NotificationController.php
+++ b/controller/NotificationController.php
@@ -161,6 +161,25 @@ class EchoNotificationController {
 		self::resetNotificationCount( $user, DB_MASTER );
 	}
 
+	/**
+	 * @param $user User to mark all notifications read for
+	 * @return boolean
+	 */
+	public static function markAllRead( $user ) {
+		global $wgEchoBackend, $wgEchoMaxNotificationCount;
+
+		$notificationCount = self::getNotificationCount( $user );
+		// Only update all the unread notifications if it isn't a huge number.
+		// TODO: Implement batched jobs it's over the maximum.
+		if ( $notificationCount <= $wgEchoMaxNotificationCount ) {
+			$wgEchoBackend->markAllRead( $user );
+			self::resetNotificationCount( $user, DB_MASTER );
+			return true;
+		} else {
+			return false;
+		}
+	}
+
 	/**
 	 * Recalculates the number of notifications that a user has.
 	 *
diff --git a/includes/DbEchoBackend.php b/includes/DbEchoBackend.php
index 32b249661..83cad7076 100644
--- a/includes/DbEchoBackend.php
+++ b/includes/DbEchoBackend.php
@@ -227,6 +227,23 @@ class MWDbEchoBackend extends MWEchoBackend {
 		);
 	}
 
+	/**
+	 * @param $user User
+	 */
+	public function markAllRead( $user ) {
+		$this->dbw->update(
+			'echo_notification',
+			array( 'notification_read_timestamp' => $this->dbw->timestamp( wfTimestampNow() ) ),
+			array(
+				'notification_user' => $user->getId(),
+				'notification_read_timestamp' => NULL,
+				'notification_bundle_base' => 1,
+			),
+			__METHOD__,
+			array( 'LIMIT' => 500 )
+		);
+	}
+
 	/**
 	 * @param $user User object to check notifications for
 	 * @param $dbSource string use master or slave storage to pull count
diff --git a/includes/EchoBackend.php b/includes/EchoBackend.php
index a3dc9c383..2ee2ba113 100644
--- a/includes/EchoBackend.php
+++ b/includes/EchoBackend.php
@@ -115,6 +115,12 @@ abstract class MWEchoBackend {
 	 */
 	abstract public function markRead( $user, $eventIDs );
 
+	/**
+	 * Mark all unread notifications as read for a user
+	 * @param $user User
+	 */
+	abstract public function markAllRead( $user );
+
 	/**
 	 * Retrieves number of unread notifications that a user has.
 	 * @param $user User object to check notifications for
diff --git a/modules/overlay/ext.echo.overlay.css b/modules/overlay/ext.echo.overlay.css
index 4aeec019d..4c5af355c 100644
--- a/modules/overlay/ext.echo.overlay.css
+++ b/modules/overlay/ext.echo.overlay.css
@@ -58,9 +58,12 @@
 .mw-echo-overlay-title {
 	/*border-bottom: 1px solid #A7D7F9;*/
 	font-size: 13px;
-	padding: 15px 15px 15px 60px;
+	line-height: 15px;
+	height: 15px;
+	padding: 15px 15px 15px 28px;
 	border-bottom: 1px solid #DDDDDD;
 	font-weight: bold;
+	position: relative;
 }
 
 #mw-echo-overlay-footer {
@@ -113,3 +116,13 @@
 	border-bottom: 1px solid #DDDDDD;
 	padding: 15px 15px 10px 60px;
 }
+
+#mw-echo-mark-read-button {
+	position: absolute;
+	bottom: 12px;
+	right: 15px;
+	padding: 1px 8px;
+	font-size: 11px;
+	line-height: 15px;
+	font-weight: normal;
+}
diff --git a/modules/overlay/ext.echo.overlay.js b/modules/overlay/ext.echo.overlay.js
index cfbd589aa..e57566e43 100644
--- a/modules/overlay/ext.echo.overlay.js
+++ b/modules/overlay/ext.echo.overlay.js
@@ -58,7 +58,9 @@
 						$title = $( '<div class="mw-echo-overlay-title"></div>' ),
 						$ul = $( '<ul class="mw-echo-notifications"></ul>' ),
 						titleText = '',
-						$overlayFooter;
+						overflow = false,
+						$overlayFooter,
+						$markReadButton;
 
 					$ul.css( 'max-height', notificationLimit * 95 + 'px' );
 					$.each( notifications.index, function( index, id ) {
@@ -84,15 +86,57 @@
 					} );
 
 					if ( notifications.index.length > 0 ) {
-						if ( unreadTotalCount > unread.length ) {
+						if ( isNaN( unreadTotalCount ) || unreadTotalCount > unread.length ) {
 							titleText = mw.msg( 'echo-overlay-title-overflow', unread.length, unreadTotalCount );
+							overflow = true;
 						} else {
 							titleText =  mw.msg( 'echo-overlay-title' );
 						}
 					} else {
 						titleText = mw.msg( 'echo-none' );
 					}
-					$title.text( titleText );
+
+					$markReadButton = $( '<button/>' )
+						.addClass( 'mw-ui-button' )
+						.attr( 'id', 'mw-echo-mark-read-button' )
+						.text( mw.msg( 'echo-mark-all-as-read' ) )
+						.click( function( e ) {
+							e.preventDefault();
+							Api.get( {
+								'action' : 'query',
+								'meta' : 'notifications',
+								'notmarkallread' : true,
+								'notprop' : 'count'
+							}, {
+								'ok' : function( result ) {
+									if ( result.query.notifications.count !== undefined ) {
+										count = result.query.notifications.count;
+										mw.echo.overlay.updateCount( count );
+										// Reset header to 'Notifications'
+										$( '#echo-overlay-title-text').text( mw.msg( 'echo-overlay-title' ) );
+									}
+								}
+							} );
+						} );
+
+					// If there are more unread notifications than can fit in the overlay,
+					// but fewer than the maximum count, show the 'mark all as read' button.
+					// The only reason we limit it to the maximum is to prevent expensive
+					// database updates. If the count is more than the maximum, it could
+					// be thousands.
+					if ( overflow &&
+						!isNaN( unreadTotalCount ) &&
+						unreadTotalCount < mw.echo.overlay.configuration['max-notification-count']
+					) {
+						// Add the 'mark all as read' button to the title area
+						$title.append( $markReadButton );
+					}
+					// Add the header to the title area
+					$( '<div/>' )
+						.attr( 'id', 'echo-overlay-title-text' )
+						.text( titleText )
+						.appendTo( $title );
+					// Insert the title area into the overlay
 					$title.appendTo( $overlay );
 
 					if ( $ul.find( 'li' ).length ) {