diff --git a/src/wp-includes/canonical.php b/src/wp-includes/canonical.php
index 964e56c6148fa..b14e2ac5bcf37 100644
--- a/src/wp-includes/canonical.php
+++ b/src/wp-includes/canonical.php
@@ -1067,4 +1067,23 @@ function wp_redirect_admin_locations() {
 		wp_redirect( wp_login_url() );
 		exit;
 	}
+
+	$password_change_urls = array(
+		'/.well-known/change-password',
+		home_url( '.well-known/change-password', 'relative' ),
+		site_url( '.well-known/change-password', 'relative' ),
+	);
+
+	if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $password_change_urls, true ) ) {
+		/**
+		 * Filters the URL to redirect to when a browser or password manager
+		 * requests the well-known change-password URL (/.well-known/change-password).
+		 *
+		 * @since 6.9.0
+		 *
+		 * @param string $url The URL to redirect to. Default is the user profile page.
+		 */
+		wp_redirect( apply_filters( 'wp_change_password_url', admin_url( 'profile.php' ) ) );
+		exit;
+	}
 }
diff --git a/tests/phpunit/tests/canonical/changePassword.php b/tests/phpunit/tests/canonical/changePassword.php
new file mode 100644
index 0000000000000..9ffdf1b5760b3
--- /dev/null
+++ b/tests/phpunit/tests/canonical/changePassword.php
@@ -0,0 +1,119 @@
+<?php
+
+/**
+ * Tests for the /.well-known/change-password redirect.
+ *
+ * @group canonical
+ * @group rewrite
+ * @group query
+ * @ticket 51173
+ */
+class Tests_Canonical_ChangePassword extends WP_UnitTestCase {
+
+	/**
+	 * Whether REQUEST_URI was set before the test.
+	 *
+	 * @var bool
+	 */
+	private $request_uri_was_set;
+
+	/**
+	 * Original REQUEST_URI value.
+	 *
+	 * @var string
+	 */
+	private $original_request_uri;
+
+	public function set_up() {
+		parent::set_up();
+		$this->request_uri_was_set  = isset( $_SERVER['REQUEST_URI'] );
+		$this->original_request_uri = $_SERVER['REQUEST_URI'] ?? '';
+		$this->set_permalink_structure( '/%postname%/' );
+	}
+
+	public function tear_down() {
+		if ( $this->request_uri_was_set ) {
+			$_SERVER['REQUEST_URI'] = $this->original_request_uri;
+		} else {
+			unset( $_SERVER['REQUEST_URI'] );
+		}
+		parent::tear_down();
+	}
+
+	/**
+	 * Returns the redirect URL triggered by wp_redirect_admin_locations()
+	 * for the given REQUEST_URI, or null if no redirect fires.
+	 *
+	 * @param string $request_uri
+	 * @return string|null
+	 */
+	private function get_redirect_for( $request_uri ) {
+		$_SERVER['REQUEST_URI'] = $request_uri;
+
+		global $wp_query;
+		$original_is_404  = $wp_query->is_404;
+		$wp_query->is_404 = true;
+
+		$captured = null;
+
+		$capture = static function ( $location ) use ( &$captured ) {
+			$captured = $location;
+			throw new RuntimeException( 'Redirect intercepted.' );
+		};
+
+		add_filter( 'wp_redirect', $capture );
+		try {
+			wp_redirect_admin_locations();
+		} catch ( RuntimeException $e ) {
+			// Redirect was intercepted; $captured holds the URL.
+		} finally {
+			remove_filter( 'wp_redirect', $capture );
+			$wp_query->is_404 = $original_is_404;
+		}
+
+		return $captured;
+	}
+
+	/**
+	 * @covers ::wp_redirect_admin_locations
+	 */
+	public function test_well_known_change_password_redirects_to_profile() {
+		$redirect = $this->get_redirect_for( '/.well-known/change-password' );
+		$this->assertNotNull( $redirect, 'A redirect should fire for the well-known change-password URL.' );
+		$this->assertStringContainsString( 'profile.php', $redirect, 'Should redirect to the profile page.' );
+	}
+
+	/**
+	 * @covers ::wp_redirect_admin_locations
+	 */
+	public function test_well_known_change_password_with_trailing_slash_redirects_to_profile() {
+		$redirect = $this->get_redirect_for( '/.well-known/change-password/' );
+		$this->assertNotNull( $redirect, 'A redirect should fire for the trailing-slash variant.' );
+		$this->assertStringContainsString( 'profile.php', $redirect, 'Trailing slash variant should also redirect to the profile page.' );
+	}
+
+	/**
+	 * @covers ::wp_redirect_admin_locations
+	 */
+	public function test_well_known_change_password_no_redirect_without_pretty_permalinks() {
+		$this->set_permalink_structure( '' );
+
+		$redirect = $this->get_redirect_for( '/.well-known/change-password' );
+
+		$this->assertNull( $redirect, 'Should not redirect when pretty permalinks are disabled.' );
+	}
+
+	/**
+	 * @covers ::wp_redirect_admin_locations
+	 */
+	public function test_wp_change_password_url_filter() {
+		$custom_url = 'https://example.com/my-account/change-password/';
+		$filter     = static fn() => $custom_url;
+
+		add_filter( 'wp_change_password_url', $filter );
+		$redirect = $this->get_redirect_for( '/.well-known/change-password' );
+		remove_filter( 'wp_change_password_url', $filter );
+
+		$this->assertSame( $custom_url, $redirect );
+	}
+}