Cheap flights from Chicago O'Hare Intl Airport to Los Angeles from $88

In general, September is the cheapest month to fly from Chicago O'Hare Intl Airport to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $352. If you aren’t able to travel during the month of September, then book flights to Ontario from Chicago O'Hare Intl Airport during January instead. Flights to Ontario in January, while not as cheap as those in September, still average around $389.

The cheapest day to depart on your flight to Ontario is on a Thursday when prices can be found for as low as $425. This is often the case because there is less demand to fly during this day of the week. When flying out on a Monday, the most expensive travel day of the week, you can expect to see flight prices from Chicago O'Hare Intl Airport to Ontario for around $718.

At noon is the cheapest time of day to fly from Chicago O'Hare Intl Airport to Ontario when you can find flight prices for as low as $301. Flying to Ontario at noon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $502 on average. Flights to Ontario from Chicago O'Hare Intl Airport in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

Fly from Chicago O'Hare Intl to Ontario for the best Chicago O'Hare Intl - Ontario flight prices

You are more likely to see cheaper flights to Ontario from Chicago O'Hare Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $446 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Chicago O'Hare Intl Airport for as low as $284 on momondo.

There are 4 cabin classes available to choose from on Chicago O'Hare Intl Airport to Ontario flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 2% on your flight if you consider stops on a Chicago O'Hare Intl Airport to Ontario flight.

As of September 2026, prices for Chicago O'Hare Intl Airport to Ontario flights are approximately 53% more expensive when compared to flights at the same time last year.

United Airlines and Delta are the most popular carriers operating from Chicago O'Hare Intl to Ontario

American Airlines, United Airlines and Frontier are the top three most popular airlines that fly to Ontario from Chicago O'Hare Intl Airport according to our data. American Airlines is the first choice among our users, with 41% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 7 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.