$79 Cheap United flights Denver (DEN) to Ontario (ONT)

View $79 flight on Thu, Oct 2, 2025Opens in a new window

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$79 Cheap United flights Denver (DEN) to Ontario (ONT)

Prices were available within the past 7 days and start at $79 for one-way flights and $157 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Thu, Oct 2 - Wed, Oct 8
DEN
Denver
ONT
Ontario
$157 Roundtrip, just found
$157
Roundtrip
just found
Select United flight, departing Thu, Oct 2 from Denver to Ontario, returning Wed, Oct 8, priced at $157 just found
Flights from Denver (DEN) to Ontario (ONT)
Origin airport
Denver Intl.
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Popular airline
Frontier Airlines
Distance
816 mi

Frequently asked questions

How much is a United Airlines flight from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Landing cheap one-way United Airlines flights from DEN to ONT from $79 on Expedia is simple --- just filter by "Price (lowest to highest)." Alternatively, check out our budget-friendly round-trip fares from $157 for your next exciting adventure.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.
What is the cheapest month to fly from DEN to ONT with United Airlines?
January is one of the cheapest months to get away to Ontario with United Airlines. You could also find great deals on one-way and round-trip fares in April.
What is the cheapest time to book flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) with United Airlines?
Look for cheap United Airlines flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) one to three months before your departure day. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. Regardless of fare type and journey, the best day to book a domestic flight is usually Sunday and the most expensive day is typically Monday. Passengers who book on a Sunday can save 6% on average compared to those who book their travel on a Monday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.
Does United Airlines fly nonstop from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Book a seat on one of United Airlines's 14 weekly direct flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT). To view available options, enter your dates, origin and destination and hit search. Then apply the "Nonstop" and "Airline" filters.
How long does it take to fly from DEN to ONT with United Airlines?
Take off from Denver Intl. Airport (DEN) for Los Angeles - Ontario Intl. Airport (ONT) on a nonstop United Airlines flight, and you'll be in the skies for around 2h 26m.
Which day of the week has the most United Airlines flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
If flexibility is what you're after, Thursday offers the most choice for United Airlines flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT). Take your pick of 2 different departures.
What is the earliest United Airlines flight from DEN to ONT?
The earliest flight from DEN to ONT with United Airlines leaves at 11:15AM UTC-7. You'll land at 12:41PM UTC-8. The last United Airlines flight of the day leaves at 7:25PM UTC-7 and arrives at 8:51PM UTC-8. With around 20% fewer cancellations for early and mid-morning flights, beginning your travel day early is often the wisest option.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports does United Airlines fly into in Ontario?
Los Angeles - Ontario Intl. Airport (ONT) is the main Ontario hub for United Airlines flights from Denver Intl. Airport (DEN). Los Angeles Intl. Airport (LAX) and John Wayne Airport (SNA) are two other possibilities. When organizing your trip through Expedia, select the "All Airports" option for your destination to see all available choices.
Why fly with United Airlines from DEN to ONT?
With a rewarding loyalty program, United Airlines is a favorite of many passengers flying from DEN to ONT. Plus, as a United Mileage Plus and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.
What type of plane does United Airlines fly from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
For the Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) route, United Airlines typically operates Airbus A320 and Boeing 737-900 planes. Remember that last-minute changes are possible for operational demands, so your flight could be on another aircraft.
Can I change or cancel my United Airlines flight from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)?
Changes are generally free within 24 hours of making a booking, but your airline may add a charge after that. For more details about altering your reservation, go to your "Trips," select your flight and click on "Manage Booking." If you'd like the freedom to adjust your plans without extra charges, check the "No cancel fee" or "Changes included" filter when planning your next getaway.

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