diff --git a/tests/phpunit/tests/general/wpLostpasswordUrl.php b/tests/phpunit/tests/general/wpLostpasswordUrl.php
new file mode 100644
index 0000000000000..553cc8de5ca7f
--- /dev/null
+++ b/tests/phpunit/tests/general/wpLostpasswordUrl.php
@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * Tests for the wp_lostpassword_url() function.
+ *
+ * @group general
+ * @group template
+ *
+ * @covers ::wp_lostpassword_url
+ */
+class Tests_General_WpLostpasswordUrl extends WP_UnitTestCase {
+
+	/**
+	 * Tests that wp_lostpassword_url() returns the default lost password URL.
+	 *
+	 * @ticket 65819
+	 */
+	public function test_wp_lostpassword_url_default() {
+		$login_path = is_multisite() ? get_site()->path . 'wp-login.php' : 'wp-login.php';
+		$expected   = add_query_arg( 'action', 'lostpassword', network_site_url( $login_path, 'login' ) );
+
+		$this->assertSame( $expected, wp_lostpassword_url() );
+	}
+
+	/**
+	 * Tests that wp_lostpassword_url() appends redirect_to query parameter.
+	 *
+	 * @ticket 65819
+	 */
+	public function test_wp_lostpassword_url_with_redirect() {
+		$redirect = 'https://example.org/dashboard';
+		$url      = wp_lostpassword_url( $redirect );
+
+		$query = wp_parse_url( $url, PHP_URL_QUERY );
+		$this->assertIsString( $query );
+
+		wp_parse_str( $query, $query_args );
+
+		$this->assertArrayHasKey( 'action', $query_args );
+		$this->assertSame( 'lostpassword', $query_args['action'] );
+		$this->assertArrayHasKey( 'redirect_to', $query_args );
+		$this->assertSame( $redirect, $query_args['redirect_to'] );
+	}
+
+	/**
+	 * Tests that the 'lostpassword_url' filter receives expected arguments and modifies the output.
+	 *
+	 * @ticket 65819
+	 */
+	public function test_wp_lostpassword_url_filtered() {
+		$filter = new MockAction();
+		add_filter( 'lostpassword_url', array( $filter, 'filter' ), 10, 2 );
+
+		$redirect = 'https://example.org/dashboard';
+		$url      = wp_lostpassword_url( $redirect );
+
+		$this->assertSame( 1, $filter->get_call_count() );
+		$args = $filter->get_args();
+		$this->assertSame( $url, $args[0][0] );
+		$this->assertSame( $redirect, $args[0][1] );
+
+		add_filter(
+			'lostpassword_url',
+			static function () {
+				return 'https://example.org/custom-lost-password';
+			}
+		);
+
+		$this->assertSame( 'https://example.org/custom-lost-password', wp_lostpassword_url() );
+	}
+}