Cheap Flights from Denver (DEN) to Ontario (ONT)

View AU$169 flight on Mon, 1 Sep. 2025Opens in a new window

Popular airlines from Denver International Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)

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Cheap Flights from Denver to Ontario (DEN-ONT)

Prices were available within the past 7 days and start at AU$169 for one-way flights and AU$521 for return, for the period specified. Prices and availability are subject to change. Additional terms apply.
Delta
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$521
Return
Found 3 days ago
Select Delta flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$521 Found 3 days ago
Delta
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$535
Return
Found 3 days ago
Select Delta flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$535 Found 3 days ago
Delta
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$548
Return
Found 3 days ago
Select Delta flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$548 Found 3 days ago
Delta
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$560
Return
Found 3 days ago
Select Delta flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$560 Found 3 days ago
American Airlines
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$565
Return
Found 3 days ago
Select American Airlines flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$565 Found 3 days ago
United
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$574
Return
Found 3 days ago
Select United flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$574 Found 3 days ago
United
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$598
Return
Found 3 days ago
Select United flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$598 Found 3 days ago
Delta
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$605
Return
Found 3 days ago
Select Delta flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$605 Found 3 days ago
Delta
Fri., 20 Jun. - Sun., 22 Jun.
DEN
Denver
ONT
Ontario
AU$609
Return
Found 4 days ago
Select Delta flight, departing Fri., 20 Jun. from Denver to Ontario, returning Sun., 22 Jun., priced at AU$609 Found 4 days ago
American Airlines
Fri., 20 Jun. - Mon., 23 Jun.
DEN
Denver
ONT
Ontario
AU$610
Return
Found 3 days ago
Select American Airlines flight, departing Fri., 20 Jun. from Denver to Ontario, returning Mon., 23 Jun., priced at AU$610 Found 3 days ago
Flight from Denver to Ontario route information
Origin airport
Denver Intl.
Destination airport
Los Angeles - Ontario Intl.
Return price
AU$521
Distance
1306 km
Average flight time
1 hour 19 mins

Your quick guide to flights from Denver to Ontario

Pick up great flights from Denver to Ontario

With Expedia, you have your pick of 11 flights a day with 20 airlines covering flights from Denver to Ontario. Whether you’re on a business trip, a family holiday or a luxury break, just enter your travel dates, hit search then check out your choice of flights. Select from return, one way or multi-city flights, and use the advance search tool if you want a direct or refundable flight. You can narrow your search to show you just your preferred cabin class and airline, too. It’s all easy. You can book direct flights from Denver to Ontario that take around 0 hours.

Find cheap flights from Denver to Ontario

From the great flight deals with prices currently ranging from AU$521 to AU$610, you can choose to see the cheapest flights first. Generally, you can book the cheapest flights from Denver to Ontario around 4 to 6 weeks in advance. If your travel dates are flexible, try to avoid weekends and peak seasons – when you are more likely to grab the lowest prices. Even last minute, there are some impressive deals. The cheapest time to fly to Ontario is normally in June.

Reasons to book your flight from Denver to Ontario with Expedia

Expedia makes it easy to find, book, and travel, with everything you need all in one place. When you enter your travel details, find fantastic deals just for you on flight tickets from Denver to Ontario across all the main airline carriers, so you can save time, dollars, and hassle finding the perfect flight. If you think your plans could change, choose refundable flights so any changes won’t cost you more. Book your flight to Ontario right now and, if you join Expedia Rewards, you earn points this time and every time you travel with Expedia.

Frequently asked questions

How much is a flight from Denver Intl. Airport (DEN) to Ontario Airport?
Round-trip tickets from DEN to Ontario Airport start from AU$521. This price is based on fares quoted within the last 7 days on Expedia for flights departing within the next year — book ASAP to avoid missing out. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from DIA airport to ONT?
Most flights can be cancelled online, but every air carrier has different terms and conditions. If you do decide to cancel your flight, check out our Customer Service Portal and follow the instructions.
How do I find cheap flights from DEN to ONT that have flexible change policies?
Many airlines offer the option to reschedule your flight without a change fee. All you pay is the difference between the original flight and the new flight. When you’re searching for Denver Airport to Los Angeles - Ontario Intl. Airport (ONT) flights, you’ll see a “no change fees” filter for you to select.
How far is the flight from Denver Airport to ONT?
A flight distance of just 1 300 kilometres separates Denver and Ontario. Once you’re up in the skies, you won’t get a chance to do much more than read the magazine in your seat pocket.
Which airlines fly direct from DEN to Los Angeles - Ontario Intl. Airport (ONT)?
A popular airline that flies from DEN to Ontario Airport is Southwest Airlines (WN). It offers 99 monthly flights. Operating 60 flights each month along this route, Frontier Airlines (F9) is another top pick.
Are DEN to ONT flight tickets cheaper when they're purchased at the last minute?
Late planners can sometimes find a bargain, with some of the cheapest airfares from Denver Airport to Ontario Airport surfacing a few weeks prior to the departure date. If you’d rather book ahead, Expedia compares and updates the best flight deals regularly — as early as 12 months in advance in some cases. It depends on the carrier though, as not all airlines quote prices that far in advance.

Explore a world of travel with Expedia

Ontario Flight Deals

Los Angeles

Denver to Los Angeles Intl.
AU$254.70

Burbank

Denver to Hollywood Burbank
AU$399.30

Long Beach

*Available to Expedia members.