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

View $79 flight on Tue, Nov 18, 2025Opens in a new window

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

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
Wed, Oct 1 - Sat, Oct 4
ONT
Ontario
DEN
Denver
$157 Roundtrip, just found
$157
Roundtrip
just found
Select United flight, departing Wed, Oct 1 from Ontario to Denver, returning Sat, Oct 4, priced at $157 just found
Flights from Ontario (ONT) to Denver (DEN)
Origin airport
Los Angeles - Ontario Intl.
Destination airport
Denver Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Hawaiian Airlines, Southwest Airlines, United
Popular airline
United
Distance
816 mi
Average flight time
3 hours 24 mins

Frequently asked questions

How much is a United Airlines flight from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN)?
Use the "Price (lowest to highest)" filter on Expedia to find cheap United Airlines return flights from $157 from ONT to DEN. Affordable one-way options from $79 are available as well.**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 ONT to DEN with United Airlines?
January is one of the least expensive months to get away to Denver with United Airlines. You could also find excellent prices on one-way and return fares in November.
What is the cheapest time to book flights from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN) with United Airlines?
To find cheap United Airlines fares from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN), start searching one to three months before your intended departure. Securing domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also affect the cost. Sunday is usually the most affordable, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your flight on a Sunday.**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 Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN)?
Depart on one of United Airlines's 14 direct weekly flights from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN). To see your choices, enter your origin, destination and dates and hit search. Then select the "Nonstop" and "Airline" filters.
How long does it take to fly from ONT to DEN with United Airlines?
Take off from Los Angeles - Ontario Intl. Airport (ONT) for Denver Intl. Airport (DEN) on a nonstop United Airlines flight, and you'll be in the skies for around 2h 19m.
Which day of the week has the most United Airlines flights from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN)?
United Airlines has the most flights from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN) on Thursday. With up to 2 daily departures, you'll get the most flexibility and choice on this day.
What is the earliest United Airlines flight from ONT to DEN?
Setting off from ONT at 5:10AM UTC-8, the earliest United Airlines flight to DEN lands at 8:29AM UTC-7. Flying earlier in the day means you're less likely to experience cancellations.* Don't like early starts? The last United Airlines flight from ONT to DEN departs at 1:45PM UTC-8 and touches down at 5:04PM UTC-7.*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 Denver?
United Airlines flights from Los Angeles - Ontario Intl. Airport (ONT) to Denver come in to Denver Intl. Airport (DEN). This is the main gateway to this city.
Why fly with United Airlines from ONT to DEN?
Fly from ONT to DEN with United Airlines and enjoy a range of benefits starting with a rewarding loyalty program. When booking through Expedia as a United Mileage Plus and One Key™ member, you may also earn OneKeyCash™* to redeem on select future travel purchases.*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 Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN)?
You'll likely be onboard a Boeing 737-900 or an Airbus A320 when flying United Airlines from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN). However, keep in mind that a different aircraft may be used due to operational demands.
Can I change or cancel my United Airlines flight from Los Angeles - Ontario Intl. Airport (ONT) to Denver Intl. Airport (DEN)?
Typically, you can cancel or change your flight, although there may be additional fees if you booked over 24 hours ago. Prefer to keep your options open? Apply the "Changes included" or "No cancel fee" filter to find flights that won't charge extra if you need to alter your plans. To make modifications, head to "Trips," select your flight and click on "Manage Booking" for more information.

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