ONT - DEN

£54 Find Cheap Flights from Ontario to Denver

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to Denver departing on 10/5. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult

KAYAK searches hundreds of travel sites at once for deals on flights to Denver

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Denver, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Denver, as well as popular online travel agencies
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Cheap Flight Deals from Ontario to Denver (ONT-DEN)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from Ontario to Denver that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.

Recent return flight deals from Ontario to Denver

KAYAK's recommended return flight deals from the most popular airlines that fly from Ontario to Denver.
Discover the best prices for you by selecting your travel dates on KAYAK.
Choose your dates
United Airlines Logo
05:05 - 08:24ONT-DEN
2h 19mdirect
United Airlines Logo
11:15 - 12:38DEN-ONT
2h 23mdirect
£107United Airlines
Find Deal
Sat, 10 May - Sun, 11 May
Southwest Logo
05:30 - 10:10ONT-DEN
3h 40m1 stop
Southwest Logo
20:50 - 23:45DEN-ONT
3h 55m1 stop
£119Southwest
Find Deal
Sat, 10 May - Sun, 11 May
Southwest Logo
05:20 - 10:45ONT-DEN
4h 25m1 stop
Southwest Logo
20:50 - 23:45DEN-ONT
3h 55m1 stop
£123Southwest
Find Deal
Fri, 2 May - Sun, 4 May
Southwest Logo
05:30 - 10:10ONT-DEN
3h 40m1 stop
Southwest Logo
16:35 - 21:45DEN-ONT
6h 10m2 stops
£124Southwest
Find Deal
Sat, 10 May - Tue, 13 May
Southwest Logo
12:50 - 20:10ONT-DEN
6h 20m2 stops
Southwest Logo
20:50 - 23:45DEN-ONT
3h 55m1 stop
£127Southwest
Find Deal
Sat, 10 May - Sun, 11 May
Southwest Logo
12:50 - 20:10ONT-DEN
6h 20m2 stops
Southwest Logo
16:35 - 21:45DEN-ONT
6h 10m2 stops
£131Southwest
Find Deal
Sat, 10 May - Tue, 13 May
Delta Logo
06:00 - 12:04ONT-DEN
5h 04m1 stop
Delta Logo
18:23 - 23:21DEN-ONT
5h 58m1 stop
£170Delta
Find Deal
Sat, 7 Jun - Sat, 14 Jun
Delta Logo
13:15 - 19:53ONT-DEN
5h 38m1 stop
Delta Logo
05:30 - 08:52DEN-ONT
4h 22m1 stop
£186Delta
Find Deal
Tue, 10 Jun - Thu, 12 Jun
Alaska Airlines Logo
16:45 - 00:05ONT-DEN
6h 20m1 stop
Alaska Airlines Logo
19:05 - 23:57DEN-ONT
5h 52m1 stop
£208Alaska Airlines
Find Deal
Thu, 29 May - Sat, 7 Jun
Alaska Airlines Logo
07:00 - 21:15ONT-DEN
13h 15m1 stop
Alaska Airlines Logo
19:05 - 23:57DEN-ONT
5h 52m1 stop
£212Alaska Airlines
Find Deal
Wed, 14 May - Sat, 24 May

Expert advice for your flight from Ontario to Denver

 
Snippets provided in this section are AI-generated based on a summarisation of KAYAK-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are specific to the author and reflect their authentic experience, which may vary significantly from the experience of others.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airlines
Air Canada

Air Canada's priority check-in opens four hours before departure, ideal for early morning flights.


Preferred Economy seats offer 10 cm extra legroom, enhancing comfort on short-haul flights.

Read more about Air Canadaby Stefanie Waldek
Frontier

Frontier's Economy Bundle includes a carry-on and seat choice, ideal for budget-conscious travelers.


Frontier's Premium Bundle offers priority boarding and extra legroom for just CA$27 more.

Read more about Frontierby Stefanie Waldek
United Airlines

United's Economy Plus offers 15 cm more legroom, enhancing comfort on domestic flights.


United offers Priority Boarding for Zone 2, ensuring overhead bin space for carry-ons.

Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on Air Canada, Frontier and United Airlines

Stefanie Waldek

Stefanie Waldek

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or out at sea, likely en route to Antarctica or the Arctic.

Read more

KAYAK's insights & trends for Ontario to Denver flights

Get data-powered insights and trends into flights from Ontario to Denver to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest month to fly from Ontario to Denver?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to Denver, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.
The cheapest month for flights from Ontario to Denver is January, where tickets cost £77 (return) on average. On the other hand, the most expensive months are March and August, where the average cost of round-trip tickets is £132 and £132 respectively.

How far in advance should I book a flight from Ontario to Denver?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Ontario to Denver, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.
To get a below average price on the flight from Ontario to Denver, you should book around 2 weeks before departure. For the absolute cheapest price, our data suggests you should book 6 weeks before departure.

Good to know - Cheap tickets from Ontario to Denver

Low season

February

High season

July

Cheapest flight

£54
Best time to beat the crowds (24% less expensive on average)
Most popular time to fly (11% more expensive on average)
Flight from Ontario to Denver

When to book flights from Ontario to Denver

Are your dates flexible? Find out the best times to travel from Ontario to Denver based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated return price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or returns with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Ontario to Denver

  • What is the cheapest flight from Ontario to Denver?

    In the last 3 days, the lowest price for a flight from Ontario to Denver was £69 for a one-way ticket and £137 for a return.

  • Which airports will I be using when flying from Ontario to Denver?

    Ontario and Denver are both served by 1 main airport. You will leave Ontario from Ontario and will be arriving at Denver Intl.

  • Which airlines offer Wi-Fi service onboard planes from Ontario to Denver?

    All the following airlines offer inflight Wi-Fi service on the Ontario to Denver flight route: Delta, Hawaiian Airlines, American Airlines, Alaska Airlines, JetBlue, Iberia, and British Airways.

  • Which aircraft models fly most regularly from Ontario to Denver?

    The Airbus A320neo is the aircraft model that flies most regularly on the Ontario to Denver flight route.

  • Which airline alliances offer flights from Ontario to Denver?

    Star Alliance is the only airline alliance operating flights between Ontario and Denver.

  • On which days can I fly direct from Ontario to Denver?

    There are direct flights from Ontario to Denver on a daily basis.

  • How does KAYAK find such low prices on flights from Ontario to Denver?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to Denver.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ontario to Denver?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Denver from Ontario is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Ontario to Denver?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional return ticket. You could then fly to Denver with an airline and back to Ontario with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ontario to Denver?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Denver from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

Prefer to fly direct from Ontario to Denver?

Find which airlines fly direct from Ontario Airport to Denver Intl Airport, which days they fly and book direct flights.

Direct departures

Ontario to Denver Intl

Monday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Tuesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Wednesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Thursday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Friday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Saturday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Sunday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

See more direct flights

Direct returns

Denver Intl to Ontario

Monday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Tuesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Wednesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Thursday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Friday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Saturday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Sunday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

See more direct flights
See more direct flights

Everything you need to know for your flight from Ontario to Denver

Information on your arrival and departure airports

Compare transportation modes for Ontario to Denver

Average priceAverage duration
Flights2h 19m
Buses£17321h 15m

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