LA/Ontario International Airport (IATA: ONT, ICAO: KONT, FAA LID: ONT) (formerly Ontario International Airport) is a public airport located two miles (3 km) east of the central business district (CBD) of Ontario, a city in San Bernardino County, California, USA. The airport covers 1,700 acres and has two runways. It is the second major international airport in the area, after Los Angeles International Airport (LAX). Ontario International Airport is typically less crowded and easier to use than LAX.

The airport is located approximately 38 miles (61 km) east of Downtown Los Angeles. Drivers can either use the San Bernardino Freeway or the Pomona Freeway to access the airport. It is also served by local buses and by private shuttles, though most passengers drive or are picked up at the airport.

The airport is dominated by Southwest Airlines who carried 49.38% of passengers in 2007. The other four airlines in the top five were United Airlines/United Express (8.64%), Delta Airlines (7.93%), US Airways (7.08%), and American Airlines (6.18%). In 2008, 6.2 million passengers used the airport.