$29 Cheap Flights from Denver (DEN) to Ontario (ONT)

View $29 flight on Wed, Feb 25, 2026Opens in a new window

Popular airlines from Denver Intl. 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 $29 for one-way flights and $58 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Wed, Jan 28 - Sun, Feb 1
DEN
Denver
ONT
Ontario
$58 Roundtrip, just found
$58
Roundtrip
just found
Select Frontier Airlines flight, departing Wed, Jan 28 from Denver to Ontario, returning Sun, Feb 1, priced at $58 just found
Frontier Airlines
Fri, Feb 6 - Sun, Feb 8
DEN
Denver
ONT
Ontario
$64 Roundtrip, found 1 day ago
$64
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Fri, Feb 6 from Denver to Ontario, returning Sun, Feb 8, priced at $64 found 1 day ago
Frontier Airlines
Fri, Feb 20 - Tue, Feb 24
DEN
Denver
ONT
Ontario
$68 Roundtrip, found 1 day ago
$68
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Fri, Feb 20 from Denver to Ontario, returning Tue, Feb 24, priced at $68 found 1 day ago
Frontier Airlines
Fri, Dec 12 - Thu, Dec 18
DEN
Denver
ONT
Ontario
$71 Roundtrip, found 19 hours ago
$71
Roundtrip
found 19 hours ago
Select Frontier Airlines flight, departing Fri, Dec 12 from Denver to Ontario, returning Thu, Dec 18, priced at $71 found 19 hours ago
Frontier Airlines
Sun, Dec 14 - Wed, Dec 24
DEN
Denver
ONT
Ontario
$73 Roundtrip, found 10 hours ago
$73
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Sun, Dec 14 from Denver to Ontario, returning Wed, Dec 24, priced at $73 found 10 hours ago
Frontier Airlines
Sun, Jan 11 - Sat, Jan 17
DEN
Denver
ONT
Ontario
$83 Roundtrip, found 19 hours ago
$83
Roundtrip
found 19 hours ago
Select Frontier Airlines flight, departing Sun, Jan 11 from Denver to Ontario, returning Sat, Jan 17, priced at $83 found 19 hours ago
United
Wed, Jan 28 - Sun, Feb 1
DEN
Denver
ONT
Ontario
$117 Roundtrip, just found
$117
Roundtrip
just found
Select United flight, departing Wed, Jan 28 from Denver to Ontario, returning Sun, Feb 1, priced at $117 just found
Southwest Airlines
Thu, Jan 8 - Sun, Jan 11
DEN
Denver
ONT
Ontario
$117 Roundtrip, just found
$117
Roundtrip
just found
Select Southwest Airlines flight, departing Thu, Jan 8 from Denver to Ontario, returning Sun, Jan 11, priced at $117 just found
Alaska Airlines
Sat, Jan 24 - Wed, Jan 28
DEN
Denver
ONT
Ontario
$176 Roundtrip, just found
$176
Roundtrip
just found
Select Alaska Airlines flight, departing Sat, Jan 24 from Denver to Ontario, returning Wed, Jan 28, priced at $176 just found
American Airlines
Wed, Jan 21 - Wed, Feb 4
DEN
Denver
ONT
Ontario
$177 Roundtrip, just found
$177
Roundtrip
just found
Select American Airlines flight, departing Wed, Jan 21 from Denver to Ontario, returning Wed, Feb 4, priced at $177 just found

Find the cheapest month to fly from Denver (DEN) to Ontario (ONT)

March is typically the cheapest month to fly

From $48 - $397 per traveler.

Alternative airports near Ontario

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to John Wayne SNA. Average driving time to city center is 42 minutes. Flights from $144
SNA
John Wayne
Average driving time to city center42 min
Flights from $144

Frequently asked questions

How much does a flight from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) cost?
Lock in a cheap one-way flight from $29 or cheap return flight from $58 from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
January is the least expensive month to fly from DEN to ONT. Traveling during an off-peak travel window is often the key to landing a great deal.
Which airlines fly direct from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Take your pick of 3 airlines that operate direct flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT). Including:

  • Southwest Airlines
  • United Airlines
  • Frontier Airlines

What is the cheapest airline that flies from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Frontier Airlines and United Airlines are some popular airlines offering competitive fares. Don't forget that flight prices from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) can change based on demand, seasonality and time of booking. With Expedia's search tool, you can easily find a DEN to ONT flight that works with your plans and budget.
How many flights per day from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
With an average of 6 direct flights departing from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) every day, you'll be cruising above the clouds before you know it.
What are the most popular departure times for flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
More people fly between DEN and ONT at 11 AM than at any other time of day. Looking to skip the crowds? Try choosing a quieter departure window and there's a chance you'll save on your ticket as well.
What day of the week has the most flights from DEN to ONT?
If you travel on a Friday, you'll get the biggest range of choices for flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT).
What is the earliest flight from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Denver Intl. Airport (DEN)'s earliest flight to Los Angeles - Ontario Intl. Airport (ONT) is at approximately 8:07AM UTC-7. With a travel duration of 2h 33m, you'll arrive at around 9:40AM UTC-8.
How long does it take to fly from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
The average flight time from DEN to ONT is 2 hours and 27 minutes, covering a distance of 820 mi.
What is the best time to fly from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Opt for a flight from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) that leaves before 3 PM to reduce the likelihood of delays. Later departures are on average 22% more likely to be canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for Ontario from Denver Intl. Airport (DEN)?
Land at any of these Ontario hubs after your direct flight from Denver Intl. Airport (DEN):

  • Los Angeles Intl. Airport (LAX)
  • John Wayne Airport (SNA)
  • Bob Hope Airport (BUR)
  • Los Angeles - Ontario Intl. Airport (ONT)
  • Long Beach Municipal Airport (LGB)

Is it cheaper to buy a plane ticket from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) last-minute?
Booking your flight from DEN to ONT shortly before your getaway is usually more expensive. However, if there's some wiggle room with your travel dates and times, you could score a cheap last-minute fare.
Is it cheaper to book a DEN to ONT flight and hotel package?
Opting for a DEN to ONT flight and hotel package is typically cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your trip in one place. Pick from our extensive range of hotels and then add activities, flights and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Generally, it's possible to reschedule or cancel your DEN to ONT flight. However, for bookings made more than 24 hours ago, additional fees may apply. Check your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find more details on our Customer Service portal.

Travel information

Origin airport
Denver Intl.
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Hawaiian Airlines, Southwest Airlines, United
Roundtrip price
$58
Distance
816 mi
Average flight time
1 hour 20 mins

Book with confidence

Denver to Ontario Flights

The cheapest times to fly from Denver to Ontario

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Denver to Ontario are during the month of January. You can find some of the cheapest flights from Denver to Ontario with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Denver to Ontario

Sunday is one of the best days to book for cheap flights from Denver to Ontario: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Denver to Ontario

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Denver to Ontario in 2025. You can also book with separate airlines for your outbound and return journeys, from $29 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Denver to Ontario flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Denver to Ontario airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Denver to Ontario Flights

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