diff --git a/src/wp-admin/admin-header.php b/src/wp-admin/admin-header.php
index b5bbec0e98..9799d0f8d4 100644
--- a/src/wp-admin/admin-header.php
+++ b/src/wp-admin/admin-header.php
@@ -33,9 +33,9 @@ get_admin_page_title();
 $title = esc_html( strip_tags( $title ) );
 
 if ( is_network_admin() )
-	$admin_title = sprintf( __( 'Network Admin: %s' ), esc_html( get_current_site()->site_name ) );
+	$admin_title = sprintf( __( 'Network Admin: %s' ), esc_html( get_network()->site_name ) );
 elseif ( is_user_admin() )
-	$admin_title = sprintf( __( 'User Dashboard: %s' ), esc_html( get_current_site()->site_name ) );
+	$admin_title = sprintf( __( 'User Dashboard: %s' ), esc_html( get_network()->site_name ) );
 else
 	$admin_title = get_bloginfo( 'name' );
 
diff --git a/src/wp-admin/includes/class-wp-ms-sites-list-table.php b/src/wp-admin/includes/class-wp-ms-sites-list-table.php
index 9ce3ffee9b..6c7bcc3b44 100644
--- a/src/wp-admin/includes/class-wp-ms-sites-list-table.php
+++ b/src/wp-admin/includes/class-wp-ms-sites-list-table.php
@@ -518,7 +518,7 @@ class WP_MS_Sites_List_Table extends WP_List_Table {
 
 		$actions['edit']	= '<a href="' . esc_url( network_admin_url( 'site-info.php?id=' . $blog['blog_id'] ) ) . '">' . __( 'Edit' ) . '</a>';
 		$actions['backend']	= "<a href='" . esc_url( get_admin_url( $blog['blog_id'] ) ) . "' class='edit'>" . __( 'Dashboard' ) . '</a>';
-		if ( get_current_site()->blog_id != $blog['blog_id'] ) {
+		if ( get_network()->site_id != $blog['blog_id'] ) {
 			if ( $blog['deleted'] == '1' ) {
 				$actions['activate']   = '<a href="' . esc_url( wp_nonce_url( network_admin_url( 'sites.php?action=confirm&amp;action2=activateblog&amp;id=' . $blog['blog_id'] ), 'activateblog_' . $blog['blog_id'] ) ) . '">' . __( 'Activate' ) . '</a>';
 			} else {
diff --git a/src/wp-admin/includes/class-wp-ms-users-list-table.php b/src/wp-admin/includes/class-wp-ms-users-list-table.php
index da00131bcd..d219efc38e 100644
--- a/src/wp-admin/includes/class-wp-ms-users-list-table.php
+++ b/src/wp-admin/includes/class-wp-ms-users-list-table.php
@@ -329,7 +329,7 @@ class WP_MS_Users_List_Table extends WP_List_Table {
 
 			$path	= ( $val->path === '/' ) ? '' : $val->path;
 			echo '<span class="site-' . $val->site_id . '" >';
-			echo '<a href="'. esc_url( network_admin_url( 'site-info.php?id=' . $val->userblog_id ) ) .'">' . str_replace( '.' . get_current_site()->domain, '', $val->domain . $path ) . '</a>';
+			echo '<a href="'. esc_url( network_admin_url( 'site-info.php?id=' . $val->userblog_id ) ) .'">' . str_replace( '.' . get_network()->domain, '', $val->domain . $path ) . '</a>';
 			echo ' <small class="row-actions">';
 			$actions = array();
 			$actions['edit'] = '<a href="'. esc_url( network_admin_url( 'site-info.php?id=' . $val->userblog_id ) ) .'">' . __( 'Edit' ) . '</a>';
diff --git a/src/wp-admin/includes/ms.php b/src/wp-admin/includes/ms.php
index b2e4f86e88..7f1e51b55b 100644
--- a/src/wp-admin/includes/ms.php
+++ b/src/wp-admin/includes/ms.php
@@ -88,7 +88,7 @@ function wpmu_delete_blog( $blog_id, $drop = false ) {
 
 	update_blog_status( $blog_id, 'deleted', 1 );
 
-	$current_site = get_current_site();
+	$current_network = get_network();
 
 	// If a full blog object is not available, do not destroy anything.
 	if ( $drop && ! $blog ) {
@@ -96,7 +96,7 @@ function wpmu_delete_blog( $blog_id, $drop = false ) {
 	}
 
 	// Don't destroy the initial, main, or root blog.
-	if ( $drop && ( 1 == $blog_id || is_main_site( $blog_id ) || ( $blog->path == $current_site->path && $blog->domain == $current_site->domain ) ) ) {
+	if ( $drop && ( 1 == $blog_id || is_main_site( $blog_id ) || ( $blog->path == $current_network->path && $blog->domain == $current_network->domain ) ) ) {
 		$drop = false;
 	}
 
diff --git a/src/wp-admin/includes/schema.php b/src/wp-admin/includes/schema.php
index 8ddc13940a..cd66e1924b 100644
--- a/src/wp-admin/includes/schema.php
+++ b/src/wp-admin/includes/schema.php
@@ -527,7 +527,7 @@ function populate_options() {
 	// 3.0 multisite
 	if ( is_multisite() ) {
 		/* translators: site tagline */
-		$options[ 'blogdescription' ] = sprintf(__('Just another %s site'), get_current_site()->site_name );
+		$options[ 'blogdescription' ] = sprintf(__('Just another %s site'), get_network()->site_name );
 		$options[ 'permalink_structure' ] = '/%year%/%monthnum%/%day%/%postname%/';
 	}
 
diff --git a/src/wp-admin/includes/upgrade.php b/src/wp-admin/includes/upgrade.php
index 6b04963aa8..f37fcccf9d 100644
--- a/src/wp-admin/includes/upgrade.php
+++ b/src/wp-admin/includes/upgrade.php
@@ -161,12 +161,12 @@ function wp_install_defaults( $user_id ) {
 		}
 
 		$first_post = sprintf( $first_post,
-			sprintf( '<a href="%s">%s</a>', esc_url( network_home_url() ), get_current_site()->site_name )
+			sprintf( '<a href="%s">%s</a>', esc_url( network_home_url() ), get_network()->site_name )
 		);
 
 		// Back-compat for pre-4.4
 		$first_post = str_replace( 'SITE_URL', esc_url( network_home_url() ), $first_post );
-		$first_post = str_replace( 'SITE_NAME', get_current_site()->site_name, $first_post );
+		$first_post = str_replace( 'SITE_NAME', get_network()->site_name, $first_post );
 	} else {
 		$first_post = __( 'Welcome to WordPress. This is your first post. Edit or delete it, then start writing!' );
 	}
diff --git a/src/wp-admin/ms-delete-site.php b/src/wp-admin/ms-delete-site.php
index a790fa2691..3e77bbdbe9 100644
--- a/src/wp-admin/ms-delete-site.php
+++ b/src/wp-admin/ms-delete-site.php
@@ -18,7 +18,7 @@ if ( ! current_user_can( 'delete_site' ) )
 if ( isset( $_GET['h'] ) && $_GET['h'] != '' && get_option( 'delete_blog_hash' ) != false ) {
 	if ( hash_equals( get_option( 'delete_blog_hash' ), $_GET['h'] ) ) {
 		wpmu_delete_blog( $wpdb->blogid );
-		wp_die( sprintf( __( 'Thank you for using %s, your site has been deleted. Happy trails to you until we meet again.' ), $current_site->site_name ) );
+		wp_die( sprintf( __( 'Thank you for using %s, your site has been deleted. Happy trails to you until we meet again.' ), get_network()->site_name ) );
 	} else {
 		wp_die( __( "I'm sorry, the link you clicked is stale. Please select another option." ) );
 	}
@@ -70,7 +70,7 @@ Webmaster
 
 	$content = str_replace( '###USERNAME###', $user->user_login, $content );
 	$content = str_replace( '###URL_DELETE###', $url_delete, $content );
-	$content = str_replace( '###SITE_NAME###', $current_site->site_name, $content );
+	$content = str_replace( '###SITE_NAME###', get_network()->site_name, $content );
 
 	wp_mail( get_option( 'admin_email' ), "[ " . wp_specialchars_decode( get_option( 'blogname' ) ) . " ] ".__( 'Delete My Site' ), $content );
 	?>
@@ -79,7 +79,7 @@ Webmaster
 
 <?php } else {
 	?>
-	<p><?php printf( __( 'If you do not want to use your %s site any more, you can delete it using the form below. When you click <strong>Delete My Site Permanently</strong> you will be sent an email with a link in it. Click on this link to delete your site.'), $current_site->site_name); ?></p>
+	<p><?php printf( __( 'If you do not want to use your %s site any more, you can delete it using the form below. When you click <strong>Delete My Site Permanently</strong> you will be sent an email with a link in it. Click on this link to delete your site.'), get_network()->site_name); ?></p>
 	<p><?php _e( 'Remember, once deleted your site cannot be restored.' ) ?></p>
 
 	<form method="post" name="deletedirect">
diff --git a/src/wp-admin/network/settings.php b/src/wp-admin/network/settings.php
index 07f2a26e3f..5d81cdf369 100644
--- a/src/wp-admin/network/settings.php
+++ b/src/wp-admin/network/settings.php
@@ -104,7 +104,7 @@ if ( isset( $_GET['updated'] ) ) {
 			<tr>
 				<th scope="row"><label for="site_name"><?php _e( 'Network Title' ) ?></label></th>
 				<td>
-					<input name="site_name" type="text" id="site_name" class="regular-text" value="<?php echo esc_attr( $current_site->site_name ) ?>" />
+					<input name="site_name" type="text" id="site_name" class="regular-text" value="<?php echo esc_attr( get_network()->site_name ) ?>" />
 				</td>
 			</tr>
 
diff --git a/src/wp-admin/network/site-new.php b/src/wp-admin/network/site-new.php
index 62346499bc..0be051ec87 100644
--- a/src/wp-admin/network/site-new.php
+++ b/src/wp-admin/network/site-new.php
@@ -86,11 +86,11 @@ if ( isset($_REQUEST['action']) && 'add-site' == $_REQUEST['action'] ) {
 	}
 
 	if ( is_subdomain_install() ) {
-		$newdomain = $domain . '.' . preg_replace( '|^www\.|', '', $current_site->domain );
-		$path      = $current_site->path;
+		$newdomain = $domain . '.' . preg_replace( '|^www\.|', '', get_network()->domain );
+		$path      = get_network()->path;
 	} else {
-		$newdomain = $current_site->domain;
-		$path      = $current_site->path . $domain . '/';
+		$newdomain = get_network()->domain;
+		$path      = get_network()->path . $domain . '/';
 	}
 
 	$password = 'N/A';
@@ -126,7 +126,7 @@ if ( isset($_REQUEST['action']) && 'add-site' == $_REQUEST['action'] ) {
 	}
 
 	$wpdb->hide_errors();
-	$id = wpmu_create_blog( $newdomain, $path, $title, $user_id, $meta, $current_site->id );
+	$id = wpmu_create_blog( $newdomain, $path, $title, $user_id, $meta, get_current_network_id() );
 	$wpdb->show_errors();
 	if ( ! is_wp_error( $id ) ) {
 		if ( ! is_super_admin( $user_id ) && !get_user_option( 'primary_blog', $user_id ) ) {
@@ -138,7 +138,7 @@ if ( isset($_REQUEST['action']) && 'add-site' == $_REQUEST['action'] ) {
 			sprintf(
 				/* translators: %s: network name */
 				__( '[%s] New Site Created' ),
-				$current_site->site_name
+				get_network()->site_name
 			),
 			sprintf(
 				/* translators: 1: user login, 2: site url, 3: site name/title */
@@ -198,9 +198,9 @@ if ( ! empty( $messages ) ) {
 			<th scope="row"><label for="site-address"><?php _e( 'Site Address (URL)' ) ?></label></th>
 			<td>
 			<?php if ( is_subdomain_install() ) { ?>
-				<input name="blog[domain]" type="text" class="regular-text" id="site-address" aria-describedby="site-address-desc" autocapitalize="none" autocorrect="off"/><span class="no-break">.<?php echo preg_replace( '|^www\.|', '', $current_site->domain ); ?></span>
+				<input name="blog[domain]" type="text" class="regular-text" id="site-address" aria-describedby="site-address-desc" autocapitalize="none" autocorrect="off"/><span class="no-break">.<?php echo preg_replace( '|^www\.|', '', get_network()->domain ); ?></span>
 			<?php } else {
-				echo $current_site->domain . $current_site->path ?><input name="blog[domain]" type="text" class="regular-text" id="site-address" aria-describedby="site-address-desc"  autocapitalize="none" autocorrect="off" />
+				echo get_network()->domain . get_network()->path ?><input name="blog[domain]" type="text" class="regular-text" id="site-address" aria-describedby="site-address-desc"  autocapitalize="none" autocorrect="off" />
 			<?php }
 			echo '<p class="description" id="site-address-desc">' . __( 'Only lowercase letters (a-z), numbers, and hyphens are allowed.' ) . '</p>';
 			?>
diff --git a/src/wp-admin/network/sites.php b/src/wp-admin/network/sites.php
index 31bf3e9724..c9cac56c27 100644
--- a/src/wp-admin/network/sites.php
+++ b/src/wp-admin/network/sites.php
@@ -87,7 +87,7 @@ if ( isset( $_GET['action'] ) ) {
 			header( 'Content-Type: text/html; charset=utf-8' );
 		}
 
-		if ( $current_site->blog_id == $id ) {
+		if ( get_network()->site_id == $id ) {
 			wp_die( __( 'Sorry, you are not allowed to change the current site.' ) );
 		}
 
@@ -126,7 +126,7 @@ if ( isset( $_GET['action'] ) ) {
 				wp_die( __( 'Sorry, you are not allowed to access this page.' ), '', array( 'response' => 403 ) );
 
 			$updated_action = 'not_deleted';
-			if ( $id != '0' && $id != $current_site->blog_id && current_user_can( 'delete_site', $id ) ) {
+			if ( $id != '0' && $id != get_network()->site_id && current_user_can( 'delete_site', $id ) ) {
 				wpmu_delete_blog( $id, true );
 				$updated_action = 'delete';
 			}
@@ -137,7 +137,7 @@ if ( isset( $_GET['action'] ) ) {
 				$doaction = $_POST['action'] != -1 ? $_POST['action'] : $_POST['action2'];
 
 				foreach ( (array) $_POST['allblogs'] as $key => $val ) {
-					if ( $val != '0' && $val != $current_site->blog_id ) {
+					if ( $val != '0' && $val != get_network()->site_id ) {
 						switch ( $doaction ) {
 							case 'delete':
 								if ( ! current_user_can( 'delete_site', $val ) )
diff --git a/src/wp-admin/network/users.php b/src/wp-admin/network/users.php
index 3f9b688dcc..46b1ee5618 100644
--- a/src/wp-admin/network/users.php
+++ b/src/wp-admin/network/users.php
@@ -72,7 +72,7 @@ if ( isset( $_GET['action'] ) ) {
 								$userfunction = 'all_spam';
 								$blogs = get_blogs_of_user( $user_id, true );
 								foreach ( (array) $blogs as $details ) {
-									if ( $details->userblog_id != $current_site->blog_id ) // main blog not a spam !
+									if ( $details->userblog_id != get_network()->site_id ) // main blog not a spam !
 										update_blog_status( $details->userblog_id, 'spam', '1' );
 								}
 								update_user_status( $user_id, 'spam', '1' );
diff --git a/src/wp-includes/admin-bar.php b/src/wp-includes/admin-bar.php
index e95cc4d81b..83deb9609e 100644
--- a/src/wp-includes/admin-bar.php
+++ b/src/wp-includes/admin-bar.php
@@ -312,10 +312,10 @@ function wp_admin_bar_site_menu( $wp_admin_bar ) {
 
 	if ( is_network_admin() ) {
 		/* translators: %s: site name */
-		$blogname = sprintf( __( 'Network Admin: %s' ), esc_html( get_current_site()->site_name ) );
+		$blogname = sprintf( __( 'Network Admin: %s' ), esc_html( get_network()->site_name ) );
 	} elseif ( is_user_admin() ) {
 		/* translators: %s: site name */
-		$blogname = sprintf( __( 'User Dashboard: %s' ), esc_html( get_current_site()->site_name ) );
+		$blogname = sprintf( __( 'User Dashboard: %s' ), esc_html( get_network()->site_name ) );
 	}
 
 	$title = wp_html_excerpt( $blogname, 40, '&hellip;' );
diff --git a/src/wp-includes/class-wp-xmlrpc-server.php b/src/wp-includes/class-wp-xmlrpc-server.php
index 59a7c226f0..6010532386 100644
--- a/src/wp-includes/class-wp-xmlrpc-server.php
+++ b/src/wp-includes/class-wp-xmlrpc-server.php
@@ -628,7 +628,7 @@ class wp_xmlrpc_server extends IXR_Server {
 
 		foreach ( $blogs as $blog ) {
 			// Don't include blogs that aren't hosted at this site.
-			if ( $blog->site_id != get_current_site()->id )
+			if ( $blog->site_id != get_current_network_id() )
 				continue;
 
 			$blog_id = $blog->userblog_id;
diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 40d4a300e1..f7879575db 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -4302,23 +4302,18 @@ function wp_suspend_cache_invalidation( $suspend = true ) {
  *
  * @since 3.0.0
  *
- * @global object $current_site
- *
  * @param int $site_id Optional. Site ID to test. Defaults to current site.
  * @return bool True if $site_id is the main site of the network, or if not
  *              running Multisite.
  */
 function is_main_site( $site_id = null ) {
-	// This is the current network's information; 'site' is old terminology.
-	global $current_site;
-
 	if ( ! is_multisite() )
 		return true;
 
 	if ( ! $site_id )
 		$site_id = get_current_blog_id();
 
-	return (int) $site_id === (int) $current_site->blog_id;
+	return (int) $site_id === (int) get_network()->site_id;
 }
 
 /**
@@ -4334,10 +4329,8 @@ function is_main_network( $network_id = null ) {
 		return true;
 	}
 
-	$current_network_id = (int) get_current_site()->id;
-
 	if ( null === $network_id ) {
-		$network_id = $current_network_id;
+		$network_id = get_current_network_id();
 	}
 
 	$network_id = (int) $network_id;
@@ -4357,11 +4350,11 @@ function get_main_network_id() {
 		return 1;
 	}
 
-	$current_site = get_current_site();
+	$current_network = get_network();
 
 	if ( defined( 'PRIMARY_NETWORK_ID' ) ) {
 		$main_network_id = PRIMARY_NETWORK_ID;
-	} elseif ( isset( $current_site->id ) && 1 === (int) $current_site->id ) {
+	} elseif ( isset( $current_network->id ) && 1 === (int) $current_network->id ) {
 		// If the current network has an ID of 1, assume it is the main network.
 		$main_network_id = 1;
 	} else {
diff --git a/src/wp-includes/http.php b/src/wp-includes/http.php
index ff89672ec1..862e456ae3 100644
--- a/src/wp-includes/http.php
+++ b/src/wp-includes/http.php
@@ -617,7 +617,7 @@ function ms_allowed_http_request_hosts( $is_external, $host ) {
 	static $queried = array();
 	if ( $is_external )
 		return $is_external;
-	if ( $host === get_current_site()->domain )
+	if ( $host === get_network()->domain )
 		return true;
 	if ( isset( $queried[ $host ] ) )
 		return $queried[ $host ];
diff --git a/src/wp-includes/link-template.php b/src/wp-includes/link-template.php
index c1ec8b33a9..c07349190e 100644
--- a/src/wp-includes/link-template.php
+++ b/src/wp-includes/link-template.php
@@ -3255,12 +3255,12 @@ function network_site_url( $path = '', $scheme = null ) {
 	if ( ! is_multisite() )
 		return site_url($path, $scheme);
 
-	$current_site = get_current_site();
+	$current_network = get_network();
 
 	if ( 'relative' == $scheme )
-		$url = $current_site->path;
+		$url = $current_network->path;
 	else
-		$url = set_url_scheme( 'http://' . $current_site->domain . $current_site->path, $scheme );
+		$url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
 
 	if ( $path && is_string( $path ) )
 		$url .= ltrim( $path, '/' );
@@ -3297,16 +3297,16 @@ function network_home_url( $path = '', $scheme = null ) {
 	if ( ! is_multisite() )
 		return home_url($path, $scheme);
 
-	$current_site = get_current_site();
+	$current_network = get_network();
 	$orig_scheme = $scheme;
 
 	if ( ! in_array( $scheme, array( 'http', 'https', 'relative' ) ) )
 		$scheme = is_ssl() && ! is_admin() ? 'https' : 'http';
 
 	if ( 'relative' == $scheme )
-		$url = $current_site->path;
+		$url = $current_network->path;
 	else
-		$url = set_url_scheme( 'http://' . $current_site->domain . $current_site->path, $scheme );
+		$url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
 
 	if ( $path && is_string( $path ) )
 		$url .= ltrim( $path, '/' );
diff --git a/src/wp-includes/load.php b/src/wp-includes/load.php
index 2aa4451067..887a6b152a 100644
--- a/src/wp-includes/load.php
+++ b/src/wp-includes/load.php
@@ -814,8 +814,6 @@ function get_current_blog_id() {
  *
  * @since 4.6.0
  *
- * @global WP_Network $current_site The current network.
- *
  * @return int The ID of the current network.
  */
 function get_current_network_id() {
@@ -823,13 +821,13 @@ function get_current_network_id() {
 		return 1;
 	}
 
-	$current_site = get_current_site();
+	$current_network = get_network();
 
-	if ( ! isset( $current_site->id ) ) {
+	if ( ! isset( $current_network->id ) ) {
 		return get_main_network_id();
 	}
 
-	return absint( $current_site->id );
+	return absint( $current_network->id );
 }
 
 /**
diff --git a/src/wp-includes/ms-blogs.php b/src/wp-includes/ms-blogs.php
index 7627d11de1..b399cfaf9c 100644
--- a/src/wp-includes/ms-blogs.php
+++ b/src/wp-includes/ms-blogs.php
@@ -81,15 +81,15 @@ function get_blogaddress_by_name( $blogname ) {
  * @return int|null The site ID, or null if no site is found for the given slug.
  */
 function get_id_from_blogname( $slug ) {
-	$current_site = get_current_site();
+	$current_network = get_network();
 	$slug = trim( $slug, '/' );
 
 	if ( is_subdomain_install() ) {
-		$domain = $slug . '.' . preg_replace( '|^www\.|', '', $current_site->domain );
-		$path = $current_site->path;
+		$domain = $slug . '.' . preg_replace( '|^www\.|', '', $current_network->domain );
+		$path = $current_network->path;
 	} else {
-		$domain = $current_site->domain;
-		$path = $current_site->path . $slug . '/';
+		$domain = $current_network->domain;
+		$path = $current_network->path . $slug . '/';
 	}
 
 	$site_ids = get_sites( array(
diff --git a/src/wp-includes/ms-default-constants.php b/src/wp-includes/ms-default-constants.php
index 98719f8ba5..5a54b88dc3 100644
--- a/src/wp-includes/ms-default-constants.php
+++ b/src/wp-includes/ms-default-constants.php
@@ -47,19 +47,19 @@ function ms_upload_constants() {
  * @since 3.0.0
  */
 function ms_cookie_constants(  ) {
-	$current_site = get_current_site();
+	$current_network = get_network();
 
 	/**
 	 * @since 1.2.0
 	 */
 	if ( !defined( 'COOKIEPATH' ) )
-		define( 'COOKIEPATH', $current_site->path );
+		define( 'COOKIEPATH', $current_network->path );
 
 	/**
 	 * @since 1.5.0
 	 */
 	if ( !defined( 'SITECOOKIEPATH' ) )
-		define( 'SITECOOKIEPATH', $current_site->path );
+		define( 'SITECOOKIEPATH', $current_network->path );
 
 	/**
 	 * @since 2.6.0
@@ -76,10 +76,10 @@ function ms_cookie_constants(  ) {
 	 * @since 2.0.0
 	 */
 	if ( !defined('COOKIE_DOMAIN') && is_subdomain_install() ) {
-		if ( !empty( $current_site->cookie_domain ) )
-			define('COOKIE_DOMAIN', '.' . $current_site->cookie_domain);
+		if ( !empty( $current_network->cookie_domain ) )
+			define('COOKIE_DOMAIN', '.' . $current_network->cookie_domain);
 		else
-			define('COOKIE_DOMAIN', '.' . $current_site->domain);
+			define('COOKIE_DOMAIN', '.' . $current_network->domain);
 	}
 }
 
diff --git a/src/wp-includes/ms-deprecated.php b/src/wp-includes/ms-deprecated.php
index 686efccc59..930c36c2c6 100644
--- a/src/wp-includes/ms-deprecated.php
+++ b/src/wp-includes/ms-deprecated.php
@@ -28,7 +28,7 @@ function get_dashboard_blog() {
     if ( $blog = get_site_option( 'dashboard_blog' ) )
         return get_blog_details( $blog );
 
-    return get_blog_details( get_current_site()->blog_id );
+    return get_blog_details( get_network()->site_id );
 }
 
 /**
diff --git a/src/wp-includes/ms-functions.php b/src/wp-includes/ms-functions.php
index ca8176124f..697da4b010 100644
--- a/src/wp-includes/ms-functions.php
+++ b/src/wp-includes/ms-functions.php
@@ -546,8 +546,8 @@ function wpmu_validate_user_signup($user_name, $user_email) {
 function wpmu_validate_blog_signup( $blogname, $blog_title, $user = '' ) {
 	global $wpdb, $domain;
 
-	$current_site = get_current_site();
-	$base = $current_site->path;
+	$current_network = get_network();
+	$base = $current_network->path;
 
 	$blog_title = strip_tags( $blog_title );
 
@@ -580,7 +580,7 @@ function wpmu_validate_blog_signup( $blogname, $blog_title, $user = '' ) {
 		$errors->add('blogname',  __( 'Site name must be at least 4 characters.' ) );
 
 	// do not allow users to create a blog that conflicts with a page on the main blog.
-	if ( !is_subdomain_install() && $wpdb->get_var( $wpdb->prepare( "SELECT post_name FROM " . $wpdb->get_blog_prefix( $current_site->blog_id ) . "posts WHERE post_type = 'page' AND post_name = %s", $blogname ) ) )
+	if ( !is_subdomain_install() && $wpdb->get_var( $wpdb->prepare( "SELECT post_name FROM " . $wpdb->get_blog_prefix( $current_network->site_id ) . "posts WHERE post_type = 'page' AND post_name = %s", $blogname ) ) )
 		$errors->add( 'blogname', __( 'Sorry, you may not use that site name.' ) );
 
 	// all numeric?
@@ -612,7 +612,7 @@ function wpmu_validate_blog_signup( $blogname, $blog_title, $user = '' ) {
 		$mydomain = "$domain";
 		$path = $base.$blogname.'/';
 	}
-	if ( domain_exists($mydomain, $path, $current_site->id) )
+	if ( domain_exists($mydomain, $path, $current_network->id) )
 		$errors->add( 'blogname', __( 'Sorry, that site already exists!' ) );
 
 	if ( username_exists( $blogname ) ) {
@@ -789,7 +789,7 @@ function wpmu_signup_blog_notification( $domain, $path, $title, $user, $user_ema
 	}
 
 	// Send email with activation link.
-	if ( !is_subdomain_install() || get_current_site()->id != 1 )
+	if ( !is_subdomain_install() || get_current_network_id() != 1 )
 		$activate_url = network_site_url("wp-activate.php?key=$key");
 	else
 		$activate_url = "http://{$domain}{$path}wp-activate.php?key=$key"; // @todo use *_url() API
@@ -1334,7 +1334,7 @@ function insert_blog($domain, $path, $site_id) {
  * @param string $blog_title The title of the new site.
  */
 function install_blog( $blog_id, $blog_title = '' ) {
-	global $wpdb, $wp_roles, $current_site;
+	global $wpdb, $wp_roles;
 
 	// Cast for security
 	$blog_id = (int) $blog_id;
@@ -1363,7 +1363,7 @@ function install_blog( $blog_id, $blog_title = '' ) {
  		if ( 'https' === parse_url( get_site_option( 'siteurl' ), PHP_URL_SCHEME ) ) {
  			$siteurl = set_url_scheme( $siteurl, 'https' );
  		}
- 		if ( 'https' === parse_url( get_home_url( $current_site->blog_id ), PHP_URL_SCHEME ) ) {
+ 		if ( 'https' === parse_url( get_home_url( get_network()->site_id ), PHP_URL_SCHEME ) ) {
  			$home = set_url_scheme( $home, 'https' );
  		}
 
@@ -1375,7 +1375,7 @@ function install_blog( $blog_id, $blog_title = '' ) {
 	if ( get_site_option( 'ms_files_rewriting' ) )
 		update_option( 'upload_path', UPLOADBLOGSDIR . "/$blog_id/files" );
 	else
-		update_option( 'upload_path', get_blog_option( get_current_site()->blog_id, 'upload_path' ) );
+		update_option( 'upload_path', get_blog_option( get_network()->site_id, 'upload_path' ) );
 
 	update_option( 'blogname', wp_unslash( $blog_title ) );
 	update_option( 'admin_email', '' );
@@ -1430,7 +1430,7 @@ function install_blog_defaults($blog_id, $user_id) {
  * @return bool
  */
 function wpmu_welcome_notification( $blog_id, $user_id, $password, $title, $meta = array() ) {
-	$current_site = get_current_site();
+	$current_network = get_network();
 
 	/**
 	 * Filters whether to bypass the welcome email after site activation.
@@ -1470,7 +1470,7 @@ We hope you enjoy your new site. Thanks!
 	$url = get_blogaddress_by_id($blog_id);
 	$user = get_userdata( $user_id );
 
-	$welcome_email = str_replace( 'SITE_NAME', $current_site->site_name, $welcome_email );
+	$welcome_email = str_replace( 'SITE_NAME', $current_network->site_name, $welcome_email );
 	$welcome_email = str_replace( 'BLOG_TITLE', $title, $welcome_email );
 	$welcome_email = str_replace( 'BLOG_URL', $url, $welcome_email );
 	$welcome_email = str_replace( 'USERNAME', $user->user_login, $welcome_email );
@@ -1500,8 +1500,8 @@ We hope you enjoy your new site. Thanks!
 	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option('blog_charset') . "\"\n";
 	$message = $welcome_email;
 
-	if ( empty( $current_site->site_name ) )
-		$current_site->site_name = 'WordPress';
+	if ( empty( $current_network->site_name ) )
+		$current_network->site_name = 'WordPress';
 
 	/**
 	 * Filters the subject of the welcome email after site activation.
@@ -1510,7 +1510,7 @@ We hope you enjoy your new site. Thanks!
 	 *
 	 * @param string $subject Subject of the email.
 	 */
-	$subject = apply_filters( 'update_welcome_subject', sprintf( __( 'New %1$s Site: %2$s' ), $current_site->site_name, wp_unslash( $title ) ) );
+	$subject = apply_filters( 'update_welcome_subject', sprintf( __( 'New %1$s Site: %2$s' ), $current_network->site_name, wp_unslash( $title ) ) );
 	wp_mail( $user->user_email, wp_specialchars_decode( $subject ), $message, $message_headers );
 	return true;
 }
@@ -1531,7 +1531,7 @@ We hope you enjoy your new site. Thanks!
  * @return bool
  */
 function wpmu_welcome_user_notification( $user_id, $password, $meta = array() ) {
-	$current_site = get_current_site();
+	$current_network = get_network();
 
 	/**
  	 * Filters whether to bypass the welcome email after user activation.
@@ -1564,7 +1564,7 @@ function wpmu_welcome_user_notification( $user_id, $password, $meta = array() )
 	 * @param array  $meta          Signup meta data.
 	 */
 	$welcome_email = apply_filters( 'update_welcome_user_email', $welcome_email, $user_id, $password, $meta );
-	$welcome_email = str_replace( 'SITE_NAME', $current_site->site_name, $welcome_email );
+	$welcome_email = str_replace( 'SITE_NAME', $current_network->site_name, $welcome_email );
 	$welcome_email = str_replace( 'USERNAME', $user->user_login, $welcome_email );
 	$welcome_email = str_replace( 'PASSWORD', $password, $welcome_email );
 	$welcome_email = str_replace( 'LOGINLINK', wp_login_url(), $welcome_email );
@@ -1578,8 +1578,8 @@ function wpmu_welcome_user_notification( $user_id, $password, $meta = array() )
 	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option('blog_charset') . "\"\n";
 	$message = $welcome_email;
 
-	if ( empty( $current_site->site_name ) )
-		$current_site->site_name = 'WordPress';
+	if ( empty( $current_network->site_name ) )
+		$current_network->site_name = 'WordPress';
 
 	/**
 	 * Filters the subject of the welcome email after user activation.
@@ -1588,7 +1588,7 @@ function wpmu_welcome_user_notification( $user_id, $password, $meta = array() )
 	 *
 	 * @param string $subject Subject of the email.
 	 */
-	$subject = apply_filters( 'update_welcome_user_subject', sprintf( __( 'New %1$s User: %2$s' ), $current_site->site_name, $user->user_login) );
+	$subject = apply_filters( 'update_welcome_user_subject', sprintf( __( 'New %1$s User: %2$s' ), $current_network->site_name, $user->user_login) );
 	wp_mail( $user->user_email, wp_specialchars_decode( $subject ), $message, $message_headers );
 	return true;
 }
@@ -1877,7 +1877,7 @@ function global_terms( $term_id, $deprecated = '' ) {
  * @return array The current site's domain
  */
 function redirect_this_site( $deprecated = '' ) {
-	return array( get_current_site()->domain );
+	return array( get_network()->domain );
 }
 
 /**
@@ -2024,7 +2024,7 @@ function add_new_user_to_blog( $user_id, $password, $meta ) {
 	if ( !empty( $meta[ 'add_to_blog' ] ) ) {
 		$blog_id = $meta[ 'add_to_blog' ];
 		$role = $meta[ 'new_role' ];
-		remove_user_from_blog($user_id, get_current_site()->blog_id); // remove user from main blog.
+		remove_user_from_blog($user_id, get_network()->site_id); // remove user from main blog.
 		add_user_to_blog( $blog_id, $user_id, $role );
 		update_user_meta( $user_id, 'primary_blog', $blog_id );
 	}
@@ -2038,7 +2038,7 @@ function add_new_user_to_blog( $user_id, $password, $meta ) {
  * @param PHPMailer $phpmailer The PHPMailer instance, passed by reference.
  */
 function fix_phpmailer_messageid( $phpmailer ) {
-	$phpmailer->Hostname = get_current_site()->domain;
+	$phpmailer->Hostname = get_network()->domain;
 }
 
 /**
diff --git a/src/wp-includes/ms-load.php b/src/wp-includes/ms-load.php
index a516327399..31bf9ca31a 100644
--- a/src/wp-includes/ms-load.php
+++ b/src/wp-includes/ms-load.php
@@ -97,7 +97,7 @@ function ms_site_check() {
 		if ( file_exists( WP_CONTENT_DIR . '/blog-inactive.php' ) ) {
 			return WP_CONTENT_DIR . '/blog-inactive.php';
 		} else {
-			$admin_email = str_replace( '@', ' AT ', get_site_option( 'admin_email', 'support@' . get_current_site()->domain ) );
+			$admin_email = str_replace( '@', ' AT ', get_site_option( 'admin_email', 'support@' . get_network()->domain ) );
 			wp_die(
 				/* translators: %s: admin email link */
 				sprintf( __( 'This site has not been activated yet. If you are having problems activating your site, please contact %s.' ),
diff --git a/src/wp-includes/option.php b/src/wp-includes/option.php
index 4c1796f067..1554a1d8ec 100644
--- a/src/wp-includes/option.php
+++ b/src/wp-includes/option.php
@@ -1069,8 +1069,7 @@ function update_site_option( $option, $value ) {
  *
  * @see get_option()
  *
- * @global wpdb   $wpdb
- * @global object $current_site
+ * @global wpdb $wpdb
  *
  * @param int      $network_id ID of the network. Can be null to default to the current network ID.
  * @param string   $option     Name of option to retrieve. Expected to not be SQL-escaped.
@@ -1078,7 +1077,7 @@ function update_site_option( $option, $value ) {
  * @return mixed Value set for the option.
  */
 function get_network_option( $network_id, $option, $default = false ) {
-	global $wpdb, $current_site;
+	global $wpdb;
 
 	if ( $network_id && ! is_numeric( $network_id ) ) {
 		return false;
@@ -1087,8 +1086,8 @@ function get_network_option( $network_id, $option, $default = false ) {
 	$network_id = (int) $network_id;
 
 	// Fallback to the current network if a network ID is not specified.
-	if ( ! $network_id && is_multisite() ) {
-		$network_id = $current_site->id;
+	if ( ! $network_id ) {
+		$network_id = get_current_network_id();
 	}
 
 	/**
@@ -1186,8 +1185,7 @@ function get_network_option( $network_id, $option, $default = false ) {
  *
  * @see add_option()
  *
- * @global wpdb   $wpdb
- * @global object $current_site
+ * @global wpdb $wpdb
  *
  * @param int    $network_id ID of the network. Can be null to default to the current network ID.
  * @param string $option     Name of option to add. Expected to not be SQL-escaped.
@@ -1195,7 +1193,7 @@ function get_network_option( $network_id, $option, $default = false ) {
  * @return bool False if option was not added and true if option was added.
  */
 function add_network_option( $network_id, $option, $value ) {
-	global $wpdb, $current_site;
+	global $wpdb;
 
 	if ( $network_id && ! is_numeric( $network_id ) ) {
 		return false;
@@ -1204,8 +1202,8 @@ function add_network_option( $network_id, $option, $value ) {
 	$network_id = (int) $network_id;
 
 	// Fallback to the current network if a network ID is not specified.
-	if ( ! $network_id && is_multisite() ) {
-		$network_id = $current_site->id;
+	if ( ! $network_id ) {
+		$network_id = get_current_network_id();
 	}
 
 	wp_protect_special_option( $option );
@@ -1296,15 +1294,14 @@ function add_network_option( $network_id, $option, $value ) {
  *
  * @see delete_option()
  *
- * @global wpdb   $wpdb
- * @global object $current_site
+ * @global wpdb $wpdb
  *
  * @param int    $network_id ID of the network. Can be null to default to the current network ID.
  * @param string $option     Name of option to remove. Expected to not be SQL-escaped.
  * @return bool True, if succeed. False, if failure.
  */
 function delete_network_option( $network_id, $option ) {
-	global $wpdb, $current_site;
+	global $wpdb;
 
 	if ( $network_id && ! is_numeric( $network_id ) ) {
 		return false;
@@ -1313,8 +1310,8 @@ function delete_network_option( $network_id, $option ) {
 	$network_id = (int) $network_id;
 
 	// Fallback to the current network if a network ID is not specified.
-	if ( ! $network_id && is_multisite() ) {
-		$network_id = $current_site->id;
+	if ( ! $network_id ) {
+		$network_id = get_current_network_id();
 	}
 
 	/**
@@ -1378,8 +1375,7 @@ function delete_network_option( $network_id, $option ) {
  *
  * @see update_option()
  *
- * @global wpdb   $wpdb
- * @global object $current_site
+ * @global wpdb $wpdb
  *
  * @param int      $network_id ID of the network. Can be null to default to the current network ID.
  * @param string   $option     Name of option. Expected to not be SQL-escaped.
@@ -1387,7 +1383,7 @@ function delete_network_option( $network_id, $option ) {
  * @return bool False if value was not updated and true if value was updated.
  */
 function update_network_option( $network_id, $option, $value ) {
-	global $wpdb, $current_site;
+	global $wpdb;
 
 	if ( $network_id && ! is_numeric( $network_id ) ) {
 		return false;
@@ -1396,8 +1392,8 @@ function update_network_option( $network_id, $option, $value ) {
 	$network_id = (int) $network_id;
 
 	// Fallback to the current network if a network ID is not specified.
-	if ( ! $network_id && is_multisite() ) {
-		$network_id = $current_site->id;
+	if ( ! $network_id ) {
+		$network_id = get_current_network_id();
 	}
 
 	wp_protect_special_option( $option );
diff --git a/src/wp-login.php b/src/wp-login.php
index b66bd6fb2d..28e09ffbe8 100644
--- a/src/wp-login.php
+++ b/src/wp-login.php
@@ -98,7 +98,7 @@ function login_header( $title = 'Log In', $message = '', $wp_error = '' ) {
 
 	if ( is_multisite() ) {
 		$login_header_url   = network_home_url();
-		$login_header_title = get_current_site()->site_name;
+		$login_header_title = get_network()->site_name;
 	} else {
 		$login_header_url   = __( 'https://wordpress.org/' );
 		$login_header_title = __( 'Powered by WordPress' );
@@ -332,7 +332,7 @@ function retrieve_password() {
 	$message .= '<' . network_site_url("wp-login.php?action=rp&key=$key&login=" . rawurlencode($user_login), 'login') . ">\r\n";
 
 	if ( is_multisite() ) {
-		$blogname = get_current_site()->site_name;
+		$blogname = get_network()->site_name;
 	} else {
 		/*
 		 * The blogname option is escaped with esc_html on the way into the database
diff --git a/src/wp-signup.php b/src/wp-signup.php
index 99bd2afb9f..6cf96b5cf0 100644
--- a/src/wp-signup.php
+++ b/src/wp-signup.php
@@ -100,7 +100,7 @@ function show_blog_form( $blogname = '', $blog_title = '', $errors = '' ) {
 		$errors = new WP_Error();
 	}
 
-	$current_site = get_current_site();
+	$current_network = get_network();
 	// Blog name
 	if ( !is_subdomain_install() )
 		echo '<label for="blogname">' . __('Site Name:') . '</label>';
@@ -112,15 +112,15 @@ function show_blog_form( $blogname = '', $blog_title = '', $errors = '' ) {
 	<?php }
 
 	if ( !is_subdomain_install() )
-		echo '<span class="prefix_address">' . $current_site->domain . $current_site->path . '</span><input name="blogname" type="text" id="blogname" value="'. esc_attr($blogname) .'" maxlength="60" /><br />';
+		echo '<span class="prefix_address">' . $current_network->domain . $current_network->path . '</span><input name="blogname" type="text" id="blogname" value="'. esc_attr($blogname) .'" maxlength="60" /><br />';
 	else
-		echo '<input name="blogname" type="text" id="blogname" value="'.esc_attr($blogname).'" maxlength="60" /><span class="suffix_address">.' . ( $site_domain = preg_replace( '|^www\.|', '', $current_site->domain ) ) . '</span><br />';
+		echo '<input name="blogname" type="text" id="blogname" value="'.esc_attr($blogname).'" maxlength="60" /><span class="suffix_address">.' . ( $site_domain = preg_replace( '|^www\.|', '', $current_network->domain ) ) . '</span><br />';
 
 	if ( ! is_user_logged_in() ) {
 		if ( ! is_subdomain_install() ) {
-			$site = $current_site->domain . $current_site->path . __( 'sitename' );
+			$site = $current_network->domain . $current_network->path . __( 'sitename' );
 		} else {
-			$site = __( 'domain' ) . '.' . $site_domain . $current_site->path;
+			$site = __( 'domain' ) . '.' . $site_domain . $current_network->path;
 		}
 
 		/* translators: %s: site address */
@@ -304,7 +304,7 @@ function signup_another_blog( $blogname = '', $blog_title = '', $errors = '' ) {
 	$blog_title = $filtered_results['blog_title'];
 	$errors = $filtered_results['errors'];
 
-	echo '<h2>' . sprintf( __( 'Get <em>another</em> %s site in seconds' ), get_current_site()->site_name ) . '</h2>';
+	echo '<h2>' . sprintf( __( 'Get <em>another</em> %s site in seconds' ), get_network()->site_name ) . '</h2>';
 
 	if ( $errors->get_error_code() ) {
 		echo '<p>' . __( 'There was a problem, please correct the form below and try again.' ) . '</p>';
@@ -532,7 +532,7 @@ function signup_user( $user_name = '', $user_email = '', $errors = '' ) {
 
 	<h2><?php
 		/* translators: %s: name of the network */
-		printf( __( 'Get your own %s account in seconds' ), get_current_site()->site_name );
+		printf( __( 'Get your own %s account in seconds' ), get_network()->site_name );
 	?></h2>
 	<form id="setupform" method="post" action="wp-signup.php" novalidate="novalidate">
 		<input type="hidden" name="stage" value="validate-user-signup" />