United operates 55 777-200ERs, which makes it the world's largest operator of the Boeing 777-200ER, as per ch-aviation. The United Airlines Boeing 777-200ER FleetCredit: ShutterstockUnited Airlines currently operates 55 Boeing 777-200ERs. The Legacy United Airlines 777-200ER FleetThe legacy United Airlines Boeing 777-200ER fleet is made up of 33 aircraft. The Former Continental Airlines 777-200ER FleetCredit: ShutterstockContinental Airlines took delivery of 22 Boeing 777-200ERs, all of which remain in service with United Airlines. Related Why United Airlines Still Relies On The Boeing 777-300ER In 2025 The big Boeing is still going strong at United.