Cheap flights from Colorado to Los Angeles from $42

In general, November is the cheapest month to fly from Colorado to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $44. If you aren’t able to travel during the month of November, then book flights to Ontario from Colorado during January instead. Flights to Ontario in January, while not as cheap as those in November, still average around $47.

The cheapest day to depart on your flight to Ontario is on a Wednesday when prices can be found for as low as $179. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Colorado to Ontario for around $254.

In the evening is the cheapest time of day to fly from Colorado to Ontario when you can find flight prices for as low as $192. 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 at noon when prices are $243 on average. Flights to Ontario from Colorado at noon are generally more expensive because this time of day is more convenient for travelers’ schedules.

Fly from Denver Intl to Ontario for the best Colorado - Ontario flight prices

You are more likely to see cheaper flights to Ontario from Colorado when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $204 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Colorado for as low as $143 on momondo.

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

Frontier, Delta, and United Airlines are the most popular carriers operating from Colorado to Ontario

Frontier, United Airlines and Southwest are the top three most popular airlines that fly to Ontario from Colorado according to our data. Frontier is the first choice among our users, with 52% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 9 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.

11 flights are operational daily from Colorado to Ontario as of June 2026. The most popular departure time for this route is 8:00AM, with 44% of flights per day taking off in the evening.

As of June 2026, there are 82 flights per week flying from Colorado to Ontario. The most common day of the week flights depart is Mon, with 17% of flights taking off on this day.