diff --git a/src/wp-admin/includes/class-wp-debug-data.php b/src/wp-admin/includes/class-wp-debug-data.php
index d83c8737685eb..428a7fdf77268 100644
--- a/src/wp-admin/includes/class-wp-debug-data.php
+++ b/src/wp-admin/includes/class-wp-debug-data.php
@@ -381,6 +381,7 @@ public static function debug_data() {
 
 		// Conditionally add debug information for multisite setups.
 		if ( is_multisite() ) {
+			$site_ID       = get_current_blog_id();
 			$network_query = new WP_Network_Query();
 			$network_ids   = $network_query->query(
 				array(
@@ -404,6 +405,11 @@ public static function debug_data() {
 				'label' => __( 'Network count' ),
 				'value' => $network_query->found_networks,
 			);
+			$info['wp-core']['fields']['site_ID']       = array(
+				'label' => __( 'Site ID' ),
+				'value' => $site_ID,
+				'debug' => $site_ID,
+			);
 		}
 
 		$info['wp-core']['fields']['user_count'] = array(