diff --git a/src/wp-includes/load.php b/src/wp-includes/load.php
index 2682b81638..5a251af21e 100644
--- a/src/wp-includes/load.php
+++ b/src/wp-includes/load.php
@@ -1140,6 +1140,19 @@ function wp_clone( $object ) {
 	return clone( $object );
 }
 
+/**
+ * Determines whether the current request is for the login screen.
+ *
+ * @since 6.1.0
+ *
+ * @see wp_login_url()
+ *
+ * @return bool True if inside WordPress login screen, false otherwise.
+ */
+function is_login_screen() {
+	return false !== stripos( wp_login_url(), $_SERVER['SCRIPT_NAME'] );
+}
+
 /**
  * Determines whether the current request is for an administrative interface page.
  *
diff --git a/tests/phpunit/tests/load/isLoginScreen.php b/tests/phpunit/tests/load/isLoginScreen.php
new file mode 100644
index 0000000000..d0cd1df9a6
--- /dev/null
+++ b/tests/phpunit/tests/load/isLoginScreen.php
@@ -0,0 +1,21 @@
+<?php
+
+/**
+ * Tests for is_login_screen().
+ *
+ * @group load.php
+ * @covers ::is_login_screen
+ */
+class Tests_Load_IsLoginScreen extends WP_UnitTestCase {
+
+	/**
+	 * @ticket 19898
+	 */
+	public function test_is_login_screen() {
+		$this->assertFalse( is_login_screen() );
+
+		$_SERVER['SCRIPT_NAME'] = '/wp-login.php';
+
+		$this->assertTrue( is_login_screen() );
+	}
+}