Cheap flights from North America to Los Angeles from $27

In general, October is the cheapest month to fly from North America to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $253. If you aren’t able to travel during the month of October, then book flights to Ontario from North America during August instead. Flights to Ontario in August, while not as cheap as those in October, still average around $280.

The cheapest day to depart on your flight to Ontario is on a Tuesday when prices can be found for as low as $297. 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 North America to Ontario for around $592.

In the evening is the cheapest time of day to fly from North America to Ontario when you can find flight prices for as low as $326. Flying to Ontario in the evening 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 afternoon when prices are $337 on average. Flights to Ontario from North America in the afternoon are generally more expensive because this time of day is more convenient for travelers’ schedules.

Fly from San Francisco to Ontario for the best North America - Ontario flight prices

You are more likely to see cheaper flights to Ontario from North America when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $408 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from North America for as low as $168 on momondo.

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

Southwest, Delta, and Frontier are the most popular carriers operating from North America to Ontario

Frontier, United Airlines and Delta are the top three most popular airlines that fly to Ontario from North America according to our data. Frontier is the first choice among our users, with 33% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 14 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.

As of June 2026, there are 60 flights per day flying from North America to Ontario. The most common time of day flights depart is 9:00PM, with 44% of flights taking off in the evening.

420 flights are operational weekly from North America to Ontario as of June 2026. The most popular departure day for this route is Fri, with 18% of flights per week taking off on this day.