what terminal is united airlines at ord ? United Airlines primarily operates out of Terminal 1 at O’Hare International Airport (ORD) in Chicago. This terminal serves as a hub for United’s domestic flights and includes two main concourses, B and C. Concourse B is located within the main terminal building, while Concourse C is accessible via an underground walkway. Both concourses are well-equipped with plenty of amenities, including shops, restaurants, and United Club lounges for passengers looking to relax before their flights.Terminal 1 is where most United passengers will check in and depart for their domestic flights, though it also handles a few international flights. However, for some international routes, especially those arriving into Chicago, United may utilize Terminal 5, which is the designated international terminal. Arrivals from overseas destinations are usually processed through Terminal 5, where customs and immigration services are located.