diff --git a/src/wp-includes/load.php b/src/wp-includes/load.php
index 90318acdddcb4..81c2f6eff650e 100644
--- a/src/wp-includes/load.php
+++ b/src/wp-includes/load.php
@@ -901,7 +901,6 @@ function wp_start_object_cache() {
 		wp_cache_add_global_groups(
 			array(
 				'blog-details',
-				'blog-id-cache',
 				'blog-lookup',
 				'blog_meta',
 				'global-posts',
diff --git a/src/wp-includes/ms-blogs.php b/src/wp-includes/ms-blogs.php
index 0be865fd87f13..310069e8031d1 100644
--- a/src/wp-includes/ms-blogs.php
+++ b/src/wp-includes/ms-blogs.php
@@ -555,7 +555,6 @@ function switch_to_blog( $new_blog_id, $deprecated = null ) {
 				wp_cache_add_global_groups(
 					array(
 						'blog-details',
-						'blog-id-cache',
 						'blog-lookup',
 						'blog_meta',
 						'global-posts',
@@ -650,7 +649,6 @@ function restore_current_blog() {
 				wp_cache_add_global_groups(
 					array(
 						'blog-details',
-						'blog-id-cache',
 						'blog-lookup',
 						'blog_meta',
 						'global-posts',
diff --git a/src/wp-includes/ms-functions.php b/src/wp-includes/ms-functions.php
index 38b22fcd8c79a..c26e1938675c4 100644
--- a/src/wp-includes/ms-functions.php
+++ b/src/wp-includes/ms-functions.php
@@ -350,13 +350,6 @@ function get_blog_permalink( $blog_id, $post_id ) {
 function get_blog_id_from_url( $domain, $path = '/' ) {
 	$domain = strtolower( $domain );
 	$path   = strtolower( $path );
-	$id     = wp_cache_get( md5( $domain . $path ), 'blog-id-cache' );
-
-	if ( -1 === $id ) { // Blog does not exist.
-		return 0;
-	} elseif ( $id ) {
-		return (int) $id;
-	}
 
 	$args   = array(
 		'domain'                 => $domain,
@@ -369,12 +362,9 @@ function get_blog_id_from_url( $domain, $path = '/' ) {
 	$id     = array_shift( $result );
 
 	if ( ! $id ) {
-		wp_cache_set( md5( $domain . $path ), -1, 'blog-id-cache' );
 		return 0;
 	}
 
-	wp_cache_set( md5( $domain . $path ), $id, 'blog-id-cache' );
-
 	return $id;
 }
 
diff --git a/src/wp-includes/ms-site.php b/src/wp-includes/ms-site.php
index 6399dab72e881..0916857f340ba 100644
--- a/src/wp-includes/ms-site.php
+++ b/src/wp-includes/ms-site.php
@@ -992,7 +992,6 @@ function clean_blog_cache( $blog ) {
 	wp_cache_delete( $blog_id, 'blog-details' );
 	wp_cache_delete( $blog_id . 'short', 'blog-details' );
 	wp_cache_delete( $domain_path_key, 'blog-lookup' );
-	wp_cache_delete( $domain_path_key, 'blog-id-cache' );
 	wp_cache_delete( $blog_id, 'blog_meta' );
 
 	/**
diff --git a/tests/phpunit/includes/abstract-testcase.php b/tests/phpunit/includes/abstract-testcase.php
index 3a5d52b0706a9..4eed90b8dcbb8 100644
--- a/tests/phpunit/includes/abstract-testcase.php
+++ b/tests/phpunit/includes/abstract-testcase.php
@@ -435,7 +435,6 @@ public static function flush_cache() {
 		wp_cache_add_global_groups(
 			array(
 				'blog-details',
-				'blog-id-cache',
 				'blog-lookup',
 				'blog_meta',
 				'global-posts',
diff --git a/tests/phpunit/tests/multisite/site.php b/tests/phpunit/tests/multisite/site.php
index 920a76f6a7e30..489c12e5fc684 100644
--- a/tests/phpunit/tests/multisite/site.php
+++ b/tests/phpunit/tests/multisite/site.php
@@ -232,7 +232,6 @@ public function test_data_in_cache_after_wpmu_delete_blog_drop_false() {
 		$this->assertFalse( wp_cache_get( $blog_id, 'blog-details' ) );
 		$this->assertFalse( wp_cache_get( $blog_id . 'short', 'blog-details' ) );
 		$this->assertFalse( wp_cache_get( $key, 'blog-lookup' ) );
-		$this->assertFalse( wp_cache_get( $key, 'blog-id-cache' ) );
 	}
 
 	/**
@@ -273,7 +272,6 @@ public function test_data_in_cache_after_wpmu_delete_blog_drop_true() {
 		$this->assertFalse( wp_cache_get( $blog_id, 'blog-details' ) );
 		$this->assertFalse( wp_cache_get( $blog_id . 'short', 'blog-details' ) );
 		$this->assertFalse( wp_cache_get( $key, 'blog-lookup' ) );
-		$this->assertFalse( wp_cache_get( $key, 'blog-id-cache' ) );
 	}
 
 	/**
@@ -314,7 +312,6 @@ public function test_data_in_cache_after_wpmu_delete_blog_main_site_drop_true()
 		$this->assertFalse( wp_cache_get( $blog_id, 'blog-details' ) );
 		$this->assertFalse( wp_cache_get( $blog_id . 'short', 'blog-details' ) );
 		$this->assertFalse( wp_cache_get( $key, 'blog-lookup' ) );
-		$this->assertFalse( wp_cache_get( $key, 'blog-id-cache' ) );
 	}
 
 	/**
@@ -465,7 +462,6 @@ public function test_get_blog_id_from_url() {
 
 		// Test the original response and cached response for the newly created site.
 		$this->assertSame( $blog_id, get_blog_id_from_url( $details->domain, $details->path ) );
-		$this->assertSame( $blog_id, wp_cache_get( $key, 'blog-id-cache' ) );
 	}
 
 	/**
@@ -491,7 +487,6 @@ public function test_get_blog_id_from_url_that_does_not_exist() {
 		$details = get_site( $blog_id );
 
 		$this->assertSame( 0, get_blog_id_from_url( $details->domain, 'foo' ) );
-		$this->assertSame( -1, wp_cache_get( md5( $details->domain . 'foo' ), 'blog-id-cache' ) );
 	}
 
 	/**
@@ -505,7 +500,6 @@ public function test_get_blog_id_from_url_with_deleted_flag() {
 		wpmu_delete_blog( $blog_id );
 
 		$this->assertSame( $blog_id, get_blog_id_from_url( $details->domain, $details->path ) );
-		$this->assertSame( $blog_id, wp_cache_get( $key, 'blog-id-cache' ) );
 	}
 
 	/**
@@ -518,9 +512,7 @@ public function test_get_blog_id_from_url_after_dropped() {
 		$key     = md5( $details->domain . $details->path );
 		wpmu_delete_blog( $blog_id, true );
 
-		$this->assertFalse( wp_cache_get( $key, 'blog-id-cache' ) );
 		$this->assertSame( 0, get_blog_id_from_url( $details->domain, $details->path ) );
-		$this->assertSame( -1, wp_cache_get( $key, 'blog-id-cache' ) );
 	}
 
 	/**
@@ -1042,7 +1034,6 @@ public function data_get_site_caches() {
 			array( '%blog_id%', 'blog-details' ),
 			array( '%blog_id%' . 'short', 'blog-details' ),
 			array( '%domain_path_key%', 'blog-lookup' ),
-			array( '%domain_path_key%', 'blog-id-cache' ),
 		);
 	}
 
@@ -1657,11 +1648,9 @@ public function test_wp_update_site_cleans_old_cache_on_domain_change() {
 		// Ensure all respective cache values are empty.
 		$result = array(
 			wp_cache_get( $domain_path_key_old, 'blog-lookup' ),
-			wp_cache_get( $domain_path_key_old, 'blog-id-cache' ),
 			wp_cache_get( 'current_blog_' . $old_domain, 'site-options' ),
 			wp_cache_get( 'current_blog_' . $old_domain . '/', 'site-options' ),
 			wp_cache_get( $domain_path_key_new, 'blog-lookup' ),
-			wp_cache_get( $domain_path_key_new, 'blog-id-cache' ),
 			wp_cache_get( 'current_blog_' . $new_domain, 'site-options' ),
 			wp_cache_get( 'current_blog_' . $new_domain . '/', 'site-options' ),
 		);
@@ -1712,10 +1701,8 @@ public function test_wp_update_site_cleans_old_cache_on_path_change() {
 		// Ensure all respective cache values are empty.
 		$result = array(
 			wp_cache_get( $domain_path_key_old, 'blog-lookup' ),
-			wp_cache_get( $domain_path_key_old, 'blog-id-cache' ),
 			wp_cache_get( 'current_blog_test.wordpress.org' . $old_path, 'site-options' ),
 			wp_cache_get( $domain_path_key_new, 'blog-lookup' ),
-			wp_cache_get( $domain_path_key_new, 'blog-id-cache' ),
 			wp_cache_get( 'current_blog_test.wordpress.org' . $new_path, 'site-options' ),
 		);