diff --git a/wp-comments-post.php b/wp-comments-post.php
index 2c421d327a..ef67a0799f 100644
--- a/wp-comments-post.php
+++ b/wp-comments-post.php
@@ -33,16 +33,19 @@ if ( is_wp_error( $comment ) ) {
 }
 
 $user = wp_get_current_user();
+$cookies_consent = ( isset( $_POST['wp-comment-cookies-consent'] ) );
 
 /**
  * Perform other actions when comment cookies are set.
  *
  * @since 3.4.0
+ * @since 4.9.6 The `$cookies_consent` parameter was added.
  *
- * @param WP_Comment $comment Comment object.
- * @param WP_User    $user    User object. The user may not exist.
+ * @param WP_Comment $comment         Comment object.
+ * @param WP_User    $user            Comment author's user object. The user may not exist.
+ * @param boolean    $cookies_consent Comment author's consent to store cookies.
  */
-do_action( 'set_comment_cookies', $comment, $user );
+do_action( 'set_comment_cookies', $comment, $user, $cookies_consent );
 
 $location = empty( $_POST['redirect_to'] ) ? get_comment_link( $comment ) : $_POST['redirect_to'] . '#comment-' . $comment->comment_ID;
 
diff --git a/wp-includes/comment-template.php b/wp-includes/comment-template.php
index 207c29b595..97c49e4ad8 100644
--- a/wp-includes/comment-template.php
+++ b/wp-includes/comment-template.php
@@ -2195,12 +2195,15 @@ function comment_form( $args = array(), $post_id = null ) {
 	$html_req = ( $req ? " required='required'" : '' );
 	$html5    = 'html5' === $args['format'];
 	$fields   =  array(
-		'author' => '<p class="comment-form-author">' . '<label for="author">' . __( 'Name' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
-		            '<input id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30" maxlength="245"' . $html_req . ' /></p>',
-		'email'  => '<p class="comment-form-email"><label for="email">' . __( 'Email' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
-		            '<input id="email" name="email" ' . ( $html5 ? 'type="email"' : 'type="text"' ) . ' value="' . esc_attr(  $commenter['comment_author_email'] ) . '" size="30" maxlength="100" aria-describedby="email-notes"' . $html_req  . ' /></p>',
-		'url'    => '<p class="comment-form-url"><label for="url">' . __( 'Website' ) . '</label> ' .
-		            '<input id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" maxlength="200" /></p>',
+		'author'  => '<p class="comment-form-author">' . '<label for="author">' . __( 'Name' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
+					 '<input id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30" maxlength="245"' . $html_req . ' /></p>',
+		'email'   => '<p class="comment-form-email"><label for="email">' . __( 'Email' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
+					 '<input id="email" name="email" ' . ( $html5 ? 'type="email"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_email'] ) . '" size="30" maxlength="100" aria-describedby="email-notes"' . $html_req . ' /></p>',
+		'url'     => '<p class="comment-form-url"><label for="url">' . __( 'Website' ) . '</label> ' .
+					 '<input id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" maxlength="200" /></p>',
+		'cookies' => '<p class="comment-form-cookies-consent"><label for="wp-comment-cookies-consent">' .
+					 '<input id="wp-comment-cookies-consent" name="wp-comment-cookies-consent" type="checkbox" value="yes" />' .
+					 __( 'Save my name, email, and site URL in my browser for next time I post a comment.' ) . '</label></p>',
 	);
 
 	$required_text = sprintf( ' ' . __('Required fields are marked %s'), '<span class="required">*</span>' );
diff --git a/wp-includes/comment.php b/wp-includes/comment.php
index dee7a195b3..15c7603e3a 100644
--- a/wp-includes/comment.php
+++ b/wp-includes/comment.php
@@ -522,14 +522,28 @@ function wp_queue_comments_for_comment_meta_lazyload( $comments ) {
  * Sets the cookies used to store an unauthenticated commentator's identity. Typically used
  * to recall previous comments by this commentator that are still held in moderation.
  *
- * @param WP_Comment $comment Comment object.
- * @param object     $user    Comment author's object.
- *
  * @since 3.4.0
+ * @since 4.9.6 The `$cookies_consent` parameter was added.
+ *
+ * @param WP_Comment $comment         Comment object.
+ * @param WP_User    $user            Comment author's user object. The user may not exist.
+ * @param boolean    $cookies_consent Optional. Comment author's consent to store cookies. Default true.
  */
-function wp_set_comment_cookies($comment, $user) {
-	if ( $user->exists() )
+function wp_set_comment_cookies( $comment, $user, $cookies_consent = true ) {
+	// If the user already exists, or the user opted out of cookies, don't set cookies.
+	if ( $user->exists() ) {
 		return;
+	}
+
+	if ( false === $cookies_consent ) {
+		// Remove any existing cookies.
+		$past = time() - YEAR_IN_SECONDS;
+		setcookie( 'comment_author_' . COOKIEHASH, ' ', $past, COOKIEPATH, COOKIE_DOMAIN );
+		setcookie( 'comment_author_email_' . COOKIEHASH, ' ', $past, COOKIEPATH, COOKIE_DOMAIN );
+		setcookie( 'comment_author_url_' . COOKIEHASH, ' ', $past, COOKIEPATH, COOKIE_DOMAIN );
+
+		return;
+	}
 
 	/**
 	 * Filters the lifetime of the comment cookie in seconds.
@@ -538,11 +552,11 @@ function wp_set_comment_cookies($comment, $user) {
 	 *
 	 * @param int $seconds Comment cookie lifetime. Default 30000000.
 	 */
-	$comment_cookie_lifetime = apply_filters( 'comment_cookie_lifetime', 30000000 );
+	$comment_cookie_lifetime = time() + apply_filters( 'comment_cookie_lifetime', 30000000 );
 	$secure = ( 'https' === parse_url( home_url(), PHP_URL_SCHEME ) );
-	setcookie( 'comment_author_' . COOKIEHASH, $comment->comment_author, time() + $comment_cookie_lifetime, COOKIEPATH, COOKIE_DOMAIN, $secure );
-	setcookie( 'comment_author_email_' . COOKIEHASH, $comment->comment_author_email, time() + $comment_cookie_lifetime, COOKIEPATH, COOKIE_DOMAIN, $secure );
-	setcookie( 'comment_author_url_' . COOKIEHASH, esc_url($comment->comment_author_url), time() + $comment_cookie_lifetime, COOKIEPATH, COOKIE_DOMAIN, $secure );
+	setcookie( 'comment_author_' . COOKIEHASH, $comment->comment_author, $comment_cookie_lifetime, COOKIEPATH, COOKIE_DOMAIN, $secure );
+	setcookie( 'comment_author_email_' . COOKIEHASH, $comment->comment_author_email, $comment_cookie_lifetime, COOKIEPATH, COOKIE_DOMAIN, $secure );
+	setcookie( 'comment_author_url_' . COOKIEHASH, esc_url( $comment->comment_author_url ), $comment_cookie_lifetime, COOKIEPATH, COOKIE_DOMAIN, $secure );
 }
 
 /**
diff --git a/wp-includes/default-filters.php b/wp-includes/default-filters.php
index 6bb6bc328d..db60eb45c7 100644
--- a/wp-includes/default-filters.php
+++ b/wp-includes/default-filters.php
@@ -300,7 +300,7 @@ add_action( 'do_feed_rss2',               'do_feed_rss2',
 add_action( 'do_feed_atom',               'do_feed_atom',                            10, 1 );
 add_action( 'do_pings',                   'do_all_pings',                            10, 1 );
 add_action( 'do_robots',                  'do_robots'                                      );
-add_action( 'set_comment_cookies',        'wp_set_comment_cookies',                  10, 2 );
+add_action( 'set_comment_cookies',        'wp_set_comment_cookies',                  10, 3 );
 add_action( 'sanitize_comment_cookies',   'sanitize_comment_cookies'                       );
 add_action( 'admin_print_scripts',        'print_emoji_detection_script'                   );
 add_action( 'admin_print_scripts',        'print_head_scripts',                      20    );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 6fe8391d0f..e409982d2d 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9.6-alpha-43124';
+$wp_version = '4.9.6-alpha-43127';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.