diff --git src/wp-admin/includes/user.php src/wp-admin/includes/user.php
index 5c12d3d..906f5ca 100644
--- src/wp-admin/includes/user.php
+++ src/wp-admin/includes/user.php
@@ -176,7 +176,14 @@ function edit_user( $user_id = 0 ) {
 		$user_id = wp_update_user( $user );
 	} else {
 		$user_id = wp_insert_user( $user );
-		wp_new_user_notification( $user_id, 'both' );
+		/**
+		  * Fires after a new user has been created.
+		  *
+		  * @since 4.4.0
+		  *
+		  * @param int $user_id ID of the newly created user.
+		  */
+		do_action( 'edit_user_created_user', $user_id );
 	}
 	return $user_id;
 }
@@ -503,4 +510,4 @@ this email. This invitation will expire in a few days.
 
 Please click the following link to activate your user account:
 %%s' ), get_bloginfo( 'name' ), home_url(), wp_specialchars_decode( translate_user_role( $role['name'] ) ) );
-}
\ No newline at end of file
+}
diff --git src/wp-admin/network/site-new.php src/wp-admin/network/site-new.php
index c5fa157..18088b7 100644
--- src/wp-admin/network/site-new.php
+++ src/wp-admin/network/site-new.php
@@ -91,10 +91,18 @@ if ( wp_validate_action( 'add-site' ) ) {
 	if ( !$user_id ) { // Create a new user with a random password
 		$password = wp_generate_password( 12, false );
 		$user_id = wpmu_create_user( $domain, $password, $email );
-		if ( false === $user_id )
+		if ( false === $user_id ) {
 			wp_die( __( 'There was an error creating the user.' ) );
-		else
-			wp_new_user_notification( $user_id, 'both' );
+		}
+
+		/**
+		  * Fires after a new user has been created via the network site-new.php page.
+		  *
+		  * @since 4.4.0
+		  *
+		  * @param int $user_id ID of the newly created user.
+		  */
+		do_action( 'network_site_new_created_user', $user_id );
 	}
 
 	$wpdb->hide_errors();
diff --git src/wp-admin/network/site-users.php src/wp-admin/network/site-users.php
index eb692f5..d27c79e 100644
--- src/wp-admin/network/site-users.php
+++ src/wp-admin/network/site-users.php
@@ -77,9 +77,16 @@ if ( $action ) {
 				if ( false === $user_id ) {
 		 			$update = 'err_new_dup';
 				} else {
-					wp_new_user_notification( $user_id, 'both' );
 					add_user_to_blog( $id, $user_id, $_POST['new_role'] );
 					$update = 'newuser';
+					/**
+					  * Fires after a user has been created via the network site-users.php page.
+					  *
+					  * @since 4.4.0
+					  *
+					  * @param int $user_id ID of the newly created user.
+					  */
+					do_action( 'network_site_users_created_user', $user_id );
 				}
 			}
 			break;
diff --git src/wp-admin/network/user-new.php src/wp-admin/network/user-new.php
index f2ccbb8..e0bdbe5 100644
--- src/wp-admin/network/user-new.php
+++ src/wp-admin/network/user-new.php
@@ -51,7 +51,14 @@ if ( wp_validate_action( 'add-user' ) ) {
 		if ( ! $user_id ) {
 	 		$add_user_errors = new WP_Error( 'add_user_fail', __( 'Cannot add user.' ) );
 		} else {
-			wp_new_user_notification( $user_id, 'both' );
+			/**
+			  * Fires after a new user has been created.
+			  *
+			  * @since 4.4.0
+			  *
+			  * @param int $user_id ID of the newly created user.
+			  */
+			do_action( 'network_user_new_created_user', $user_id );
 			wp_redirect( add_query_arg( array('update' => 'added'), 'user-new.php' ) );
 			exit;
 		}
diff --git src/wp-includes/default-filters.php src/wp-includes/default-filters.php
index 3d3c2f0..e7303a9 100644
--- src/wp-includes/default-filters.php
+++ src/wp-includes/default-filters.php
@@ -338,6 +338,8 @@ add_action( 'wp_split_shared_term_batch', '_wp_batch_split_terms' );
 add_action( 'comment_post', 'wp_new_comment_notify_moderator', 10, 2 );
 add_action( 'comment_post', 'wp_new_comment_notify_postauthor' );
 add_action( 'after_password_reset', 'wp_password_change_notification' );
+add_action( 'register_new_user',      'wp_send_new_user_notifications' );
+add_action( 'edit_user_created_user', 'wp_send_new_user_notifications' );
 
 /**
  * Filters formerly mixed into wp-includes
diff --git src/wp-includes/ms-default-filters.php src/wp-includes/ms-default-filters.php
index eab4fc4..08d752a 100644
--- src/wp-includes/ms-default-filters.php
+++ src/wp-includes/ms-default-filters.php
@@ -27,6 +27,9 @@ add_action( 'wpmu_new_user', 'newuser_notify_siteadmin' );
 add_action( 'wpmu_activate_user', 'add_new_user_to_blog', 10, 3 );
 add_action( 'wpmu_activate_user', 'wpmu_welcome_user_notification', 10, 3 );
 add_action( 'after_signup_user', 'wpmu_signup_user_notification', 10, 4 );
+add_action( 'network_site_new_created_user',   'wp_send_new_user_notifications' );
+add_action( 'network_site_users_created_user', 'wp_send_new_user_notifications' );
+add_action( 'network_user_new_created_user',   'wp_send_new_user_notifications' );
 add_filter( 'sanitize_user', 'strtolower' );
 
 // Blogs
diff --git src/wp-includes/user-functions.php src/wp-includes/user-functions.php
index 1feac3b..3640ea9 100644
--- src/wp-includes/user-functions.php
+++ src/wp-includes/user-functions.php
@@ -2012,12 +2012,32 @@ function register_new_user( $user_login, $user_email ) {
 
 	update_user_option( $user_id, 'default_password_nag', true, true ); //Set up the Password change nag.
 
-	wp_new_user_notification( $user_id, 'both' );
+	/**
+	 * Fires after a new user registration has been recorded.
+	 *
+	 * @since 4.4.0
+	 *
+	 * @param int $user_id ID of the newly registered user.
+	 */
+	do_action( 'register_new_user', $user_id );
 
 	return $user_id;
 }
 
 /**
+ * Initiate email notifications related to the creation of new users.
+ *
+ * Notifications are sent both to the site admin and to the newly created user.
+ *
+ * @since 4.4.0
+ *
+ * @param int $user_id ID of the newly created user.
+ */
+function wp_send_new_user_notifications( $user_id ) {
+	wp_new_user_notification( $user_id, 'both' );
+}
+
+/**
  * Retrieve the current session token from the logged_in cookie.
  *
  * @since 4.0.0