Ontario International Airport (ONT) is a medium-sized airport located in Ontario, California, United States. Southwest Airlines is one of the major carriers operating at Ontario Airport. Ontario Airport terminal southwest is Terminal 4 for both departures and arrivals.

The terminal has a range of dining options, including restaurants, cafes, and bars, where you can grab a meal or a snack before your flight. There are also several retail stores and shops available for shopping and browsing.