diff --git src/wp-admin/includes/misc.php src/wp-admin/includes/misc.php
index 090282062f..078434da5e 100644
--- src/wp-admin/includes/misc.php
+++ src/wp-admin/includes/misc.php
@@ -1531,13 +1531,24 @@ All at ###SITENAME###
 		$site_title = parse_url( home_url(), PHP_URL_HOST );
 	}
 
+	$subject = sprintf(
+	/* translators: New admin email address notification email subject. %s: Site title. */
+		__( '[%s] New Admin Email Address' ),
+		$site_title
+	);
+
+	/**
+	 * Filters the subject of the email sent when a change of site admin email address is attempted.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param string $subject      Subject of the email.
+	 */
+	$subject = apply_filters( 'new_admin_email_subject', $subject );
+
 	wp_mail(
 		$value,
-		sprintf(
-			/* translators: New admin email address notification email subject. %s: Site title. */
-			__( '[%s] New Admin Email Address' ),
-			$site_title
-		),
+		$subject,
 		$content
 	);
 
diff --git tests/phpunit/tests/admin/includesMisc.php tests/phpunit/tests/admin/includesMisc.php
index ce0ef7c6c5..2df7f66145 100644
--- tests/phpunit/tests/admin/includesMisc.php
+++ tests/phpunit/tests/admin/includesMisc.php
@@ -27,4 +27,30 @@ class Tests_Admin_IncludesMisc extends WP_UnitTestCase {
 			$this->assertSame( $v, url_shorten( $k ) );
 		}
 	}
+
+	/**
+	 * @ticket 59520
+	 */
+	public function test_new_admin_email_subject_filter() {
+		// Default value
+		$mailer = tests_retrieve_phpmailer_instance();
+		update_option_new_admin_email( 'old@example.com', 'new@example.com' );
+		$this->assertEquals( '[Test Blog] New Admin Email Address', $mailer->get_sent()->subject );
+
+		// Filtered value
+		add_filter(
+			'new_admin_email_subject',
+			function () {
+				return 'Filtered Admin Email Address';
+			},
+			10,
+			1
+		);
+
+		$mailer->mock_sent = array();
+
+		$mailer = tests_retrieve_phpmailer_instance();
+		update_option_new_admin_email( 'old@example.com', 'new@example.com' );
+		$this->assertEquals( 'Filtered Admin Email Address', $mailer->get_sent()->subject );
+	}
 }