Southwest Airlines ONT Terminal is based in Ontario International Airport's Terminal 4. This terminal offers travelers a seamless and efficient experience by incorporating Southwest's ticketing and check-in counters, as well as self-service kiosks for faster check-ins. Prior to boarding, passengers can choose from a variety of food and retail alternatives. The terminal also provides free Wi-Fi and spacious lounging areas. With easy access to parking and ground transportation, it ensures a stress-free trip around ONT.