FSX/P3D – Ontario International Airport. LA/Ontario International Airport (IATA: ONT, ICAO: KONT, FAA LID: ONT), formerly and still commonly known as Ontario International Airport, is a public airport two miles east of downtown Ontario, a city in San Bernardino County, California, USA. It is owned and operated by the Los Angeles World Airports (LAWA), an agency of the city of Los Angeles. For a number of years, the airport operated alongside Ontario Air National Guard Station, which was closed as a result of the 1995 Base Realignment and Closure Commission. By Fernando Angel Gonzalez.