$129 Find Cheap Flights from Denver to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Denver to Ontario departing on 4/14. 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
1 adult, Economy, 0 bags

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

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Denver to Ontario, 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 Denver to Ontario, as well as popular online travel agencies
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Cheap Flights from Denver to Ontario

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Toronto
Toronto1 stop$341
Ottawa
Ottawa2 stops$407
London
London1 stop$534
Toronto
Toronto1 stop$341
Ottawa
Ottawa2 stops$407
London
London1 stop$534

Book Cheap Denver to Ontario Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Denver to Ontario 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.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Denver to Ontario

Wed, Apr 8 - Mon, Apr 13
American Airlines Logo
7:00 am - 10:58 pm
DEN
-
YUL
13h 58m
1 stop
American Airlines Logo
4:16 pm - 10:47 pm
YUL
-
DEN
8h 31m
1 stop
$337American Airlines
Wed, Apr 15 - Mon, Apr 20
Multiple Airlines Logo
10:29 pm - 6:20 am
DEN
-
YYZ
29h 51m
1 stop
Multiple Airlines Logo
8:00 pm - 3:59 am
YYZ
-
DEN
9h 59m
1 stop
$341Multiple Airlines
Mon, Apr 13 - Mon, Apr 20
Multiple Airlines Logo
7:05 pm - 6:20 am
DEN
-
YYZ
9h 15m
1 stop
Multiple Airlines Logo
8:00 pm - 3:59 am
YYZ
-
DEN
9h 59m
1 stop
$343Multiple Airlines
Mon, Apr 13 - Wed, Apr 22
Multiple Airlines Logo
7:05 pm - 6:20 am
DEN
-
YYZ
9h 15m
1 stop
Multiple Airlines Logo
11:00 am - 12:19 am
YYZ
-
DEN
15h 19m
2 stops
$344Multiple Airlines
Tue, Apr 28 - Tue, May 5
Multiple Airlines Logo
7:15 am - 3:45 pm
DEN
-
YYZ
30h 30m
1 stop
Multiple Airlines Logo
9:45 am - 12:09 am
YYZ
-
DEN
16h 24m
1 stop
$345Multiple Airlines
Sun, May 10 - Sat, May 16
American Airlines Logo
6:13 am - 2:44 pm
DEN
-
YUL
6h 31m
1 stop
American Airlines Logo
7:45 am - 5:39 pm
YUL
-
DEN
11h 54m
2 stops
$346American Airlines
Sun, May 3 - Tue, May 5
WestJet Logo
12:15 pm - 5:15 pm
DEN
-
YHM
27h 00m
1 stop
WestJet Logo
6:10 pm - 11:20 am
YHM
-
DEN
19h 10m
1 stop
$616WestJet
Wed, May 6 - Tue, May 12
WestJet Logo
12:15 pm - 5:15 pm
DEN
-
YHM
27h 00m
1 stop
WestJet Logo
6:10 pm - 11:20 am
YHM
-
DEN
19h 10m
1 stop
$625WestJet
Mon, Apr 27 - Mon, May 4
Air Canada Logo
1:25 pm - 9:19 pm
DEN
-
YXU
5h 54m
1 stop
Air Canada Logo
5:40 am - 10:33 am
YXU
-
DEN
6h 53m
1 stop
$747Air Canada
Mon, Apr 27 - Fri, May 1
Air Canada Logo
1:25 pm - 9:19 pm
DEN
-
YXU
5h 54m
1 stop
Air Canada Logo
9:30 am - 7:00 pm
YXU
-
DEN
11h 30m
2 stops
$756Air Canada
Booking Insights

KAYAK's insights & trends for Denver to Ontario flights

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

What is the cheapest Denver to Ontario flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to Ontario from Denver found in the last 72 hours was to Toronto, at $529 round-trip. The most popular route is from Denver (DEN) to Toronto Pearson Intl Airport (YYZ), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $529.

What is the cheapest time of day to fly to Ontario?

The average price for all round-trip flights from Denver to Ontario depending on the time of departure, clicked by users on KAYAK in the last 2 weeks.

The cheapest time of day to fly to Ontario is generally in the afternoon, when round-trip flights cost $684 on average. Morning departures are around 4% more expensive than evening flights, on average. The most expensive time of day to fly to Ontario is generally in the morning, which is peak travel time and where the average cost of a ticket is $715.

Can I save money by flying with a layover from Denver to Ontario?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $561, prices are generally cheapest when you fly direct.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Denver to Ontario, 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 Denver to Ontario is September, when tickets cost $458 (return) on average. On the other hand, the most expensive months are February and January, when the average cost of round-trip tickets is $631 and $620 respectively.

What’s the cheapest day of the week to fly from Denver to Ontario?

The average price of all round-trip flights from Denver to Ontario clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from Denver to Ontario, look for departures on Thursdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Ontario, Friday is the cheapest day to fly and Monday is the most expensive.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Denver to Ontario, 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 Denver to Ontario, you should book around 4 weeks before departure, which saves you about 51% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 7 weeks before departure.

Good to know

Low seasonNovember
Cheapest flight$129
Best time to beat the crowds but there is an average 2% increase in price.
Most popular time to fly and prices are also 15% lower on average.
Flight from Denver to Toronto Pearson Airport

FAQs - booking Ontario flights

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

    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 Denver to Ontario.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Denver to 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 Denver to Ontario?

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

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

    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 from Denver to Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 4 airlines serving from Denver to Ontario

 
See real verified KAYAK customer reviews for airlines flying from Denver to Ontario. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Denver to Ontario? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.9
DeltaOverall score based on 8288 reviews
8.1Boarding
7.9Comfort
7.2Food
8.5Crew
7.8Entertainment
Airline reviews

Perhaps when you’re sitting in 1st class and the crew closes the bathroom for the pilots, there could be a notification other than holding your hands up as a blockade when you get there and you’re told the restrooms are closed please turn around … especially at night when visibility is poor and you’re met by a flight attendants with their arms up

10.0 ExcellentDebra, Mar 2026
PBI - ATL
Read more Delta reviews

Perhaps when you’re sitting in 1st class and the crew closes the bathroom for the pilots, there could be a notification other than holding your hands up as a blockade when you get there and you’re told the restrooms are closed please turn around … especially at night when visibility is poor and you’re met by a flight attendants with their arms up

First class is comfortable. Enjoyed a movie and was able to relax compared to coach.

Loved flying First Class. Very comfortable. The seat was amazing. Enjoyed a movie and was able to relax so much better than in coach.

We landed and sat on the tarmac for 45 minutes because they only have one gate at the airport and there was another plane running late so we had to wait

The WiFi was not working. That made for a long flight.

With Aeromexico it ended up good but with Delta it was bad because we did everything through Delta... Showed up at the Delta terminal... It was the wrong place! Nothing ever told us to go to the Aeromexico terminal. It said "in partnership with Aeromexico" but I was never instructed to check in with them or go to their terminal. We had to haul @$$ running through the airport and almost didn't make it thanks to this poor communication. 👎🏽

Absolutely no communication on why there's a delay and multiple flight time reschedules. I would have canceled the flight and drove back home if I known it was going to be rescheduled 3 or 4 times.

Another late night flight and MORE men belligerently drinking and yelling. I had to move from first to economy because they were so obnoxious and disruptive. Crazy to go from a cozy chair to cardboard when you were supposed to be in first. Delta allows was too much drinking which leads to belligerent behavior.

I was in first class and literally the men behind me were so aggressively loud I moved myself to economy. This has become so common on Delta - people using audio without headphones, and men on 12am / late night flights drinking and yelling to talk to each other which prevents anyone around them from resting. Pretty crazy to have to move from first to economy (poorer service, less comfort...). Wild wild. Looking into other airlines.

Love delta smaller commuter plane so no entertainment and paid wifi on MKE-LGA leg was extremely unreliable and slow

Flight left on time and we arrived 25 minutes early! There was a gate available when we arrived so early on a busy Sunday afternoon! Flight attendants came around twice with the drinks cart.

Sitting on the runway after we land for almost two hours! Not sure if we should blame United or Just Dumpy Vance.

Flight was late - I was downgraded from first class to coach

United overall experience is great these days. Airport experience was very organized. Staff on flight were great. App and information as good as it gets.

Great smooth flight. Had a seating change, but that was an improvement. Thanks United Airways Crew.

Flight was good but there are way to many announcements for credit cards etc.

Crew seemed a bit cranky. No seatback screens. But boarding was efficient and on time and we arrived early.

See previous note about the passenger in Denver who threw my husband's bag out of the overhead bin in order to maker room for his own. And the flight attendant back up the new passenger.

Terrible. They wouldn't allow me on my flight on the 14th..

Impressed with the service despite turbulence because of the weather. Both flights arrived before their scheduled times.

Everything was good except for flight delay, but it was because of the snow storm in the arrival airport.

The flight was cancelled less than 24 hours before departure. The alternate flight was a day later going from Grenada to Toronto to Vancouver to Calgary to Montreal. 2 days in the air. Not serious, Very bad service

I like the wider seats, Plus lots of legroom, Lacking entertainment, no tv or screen to play with

Liked in-flight wifi Did not like - nothing to complain, really. All good

The keg from Edmonton to Toronto My wife found it very cold. Other than that great flight.

Smooth flight Staff were courteous and welcoming upon entering and exiting the plane Pilot and crew provided frequent updates Leg space was not pleasant but manageable

Everything was good except I was a bit disappointed that I had to pay US $150 for bags.

Flight itself good .Landing at terminal3 and connections to terminal1,it is connections nightmare,specially for disable person

The seats very Uncomfortable, no meal and no entertainment for a 4Hours flight. Smooth Flight, Great Take off and landing. Superb crew!

The flight attendants were super! They created a cosy and warm flight atmosphere!

I want to thank Carlos at the Miami AC desk - he was amazing and went over and above to help us out. Thank you Carlos and all the best to you!!! You made our faith in AC feel great! Sincerely, David Cubitt

Flight was canceled due to mechanical issues. After a considerable wait in the queue, Air Canada customer service was very helpful to get us on another flight. I am disappointed to report our rescheduled flight is for three days from now. Three days of extra expenses and inconvenience is unacceptable.

Extremely disappointing. My original Denver–Vancouver–Bangkok itinerary was cancelled due to a crewing issue. I was not proactively supported and had to drive back home after already reaching the airport. Communication was poor throughout, and attempts to contact customer service resulted in being on hold for nearly three hours without reaching anyone. Instead of being rebooked on the same direct routing the following day, I was rerouted onto a much longer itinerary via multiple cities and airlines, which resulted in arriving approximately 30 hours later than scheduled. At Denver airport, there was no visible Air Canada representative available to properly assist. Ground staff offered no real support beyond directing passengers to a phone number. There was no clear communication, no ownership, and no meaningful customer care during a major disruption. The final journey involved three flights instead of the original two, significantly increasing travel time and stress. Overall, the handling of the cancellation and lack of customer support was unacceptable. What could have been better? Clear communication during the cancellation Accessible customer service (phone support that actually answers) Proper in-person assistance at the airport Rebooking onto a comparable routing rather than a significantly longer one

The last 3 hours it was freezing cold in row 56. Multiple people had their winter coats on and were utilizing the blankets provided by the airline. I also did not have easy access to figure out how to book my food allergy and advance for my meals. Most of everything I received was something I couldn't eat. This needs to be made more accessible. Also, I'm 5'10 which is the average height of the American male. I flew from Philadelphia to Toronto and then to Tokyo and the seats were absolutely unbearable. For that long of a flight it is impossible to get comfortable when doing anything. Flights need to have more space and stop prioritizing costs over people.

Was delayed at every point/ connection. Luggages missing for 5days. Had no medications for diabetes and high B/p. when bags where finally delivered on the 30th, the insulin and ozempic were no longer patent, as the ice pack had since dissolved and the authenticity of the med is now questionable, since they must be refrigerated. Please have them refund my bag fees. I should sue them for all the inconveniences caused to me.

The plane was delayed substantially due to a mechanical problem, that being said, the airline was very fair with providing a meal coupon for us. I would rather arrive late on a mechanically sound plane than the alternative. The food served in the plane was just awful, however and I recommend a new catering company.

I waiting for 2 hrs to retrieve my luggage. Didn't get home till 3am.

The flight left late and I didn’t get a glass of bubbly upon boarding (which I’m used to when booking business class on other flights), but otherwise it was a pleasant flight with lovely, helpful crew members and I enjoyed my meal.

Flight was canceled for a reason they knew hours before but did not mention. Next the gate chnage from 37 to 38 at least 10 times. Ridiculous.

It was just fine. I managed to make all my connection too sbut had trouble in Munich with no wheel chair and trouble trying to get help from the airport people to get to the other terminal for my flight. Finally a wonderful lady Amelia, helped me to make my flight connection Timon with zero time to spare.

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

Information on your arrival and departure airports