$110 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 4/15. 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
Travelers love KAYAK
41 299 237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Denver to Ontario

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Toronto
Toronto2 stops$261
Ottawa
Ottawa2 stops$341
London
London1 stop$443
Toronto
Toronto2 stops$261
Ottawa
Ottawa2 stops$341
London
London1 stop$443

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

Mon, Apr 13 - Mon, Apr 20
Multiple Airlines Logo
10:30 pm - 6:13 am
DEN
-
YYZ
29h 43m
2 stops
Multiple Airlines Logo
7:55 pm - 12:19 am
YYZ
-
DEN
30h 24m
1 stop
$261Multiple Airlines
Mon, Apr 20 - Fri, Apr 24
Multiple Airlines Logo
7:05 pm - 6:43 am
DEN
-
YYZ
9h 38m
1 stop
Multiple Airlines Logo
8:00 pm - 3:59 am
YYZ
-
DEN
9h 59m
1 stop
$263Multiple Airlines
Mon, Apr 20 - Fri, Apr 24
Multiple Airlines Logo
10:29 pm - 6:13 am
DEN
-
YYZ
29h 44m
2 stops
Multiple Airlines Logo
8:00 pm - 3:59 am
YYZ
-
DEN
9h 59m
1 stop
$264Multiple Airlines
Thu, Jun 4 - Mon, Jun 8
WestJet Logo
12:15 pm - 7:50 pm
DEN
-
YKF
29h 35m
1 stop
WestJet Logo
8:40 pm - 11:20 am
YKF
-
DEN
16h 40m
1 stop
$395WestJet
Wed, Mar 25 - Mon, Mar 30
Delta Logo
7:30 am - 8:30 am
DEN
-
YUL
23h 00m
1 stop
Delta Logo
7:30 pm - 10:06 am
YUL
-
DEN
16h 36m
1 stop
$396Delta
Sat, Jun 6 - Mon, Jun 8
WestJet Logo
12:15 pm - 7:50 pm
DEN
-
YKF
29h 35m
1 stop
WestJet Logo
8:40 pm - 11:20 am
YKF
-
DEN
16h 40m
1 stop
$407WestJet
Tue, Apr 14 - Tue, Apr 21
Air Canada Logo
1:25 pm - 9:19 pm
DEN
-
YXU
5h 54m
1 stop
Air Canada Logo
5:10 am - 10:18 am
YXU
-
DEN
7h 08m
1 stop
$644Air Canada
Wed, Jul 8 - Mon, Jul 13
Air Canada Logo
9:40 am - 9:40 pm
DEN
-
YXU
10h 00m
2 stops
Air Canada Logo
6:00 am - 10:32 am
YXU
-
DEN
6h 32m
1 stop
$652Air Canada
Tue, Apr 14 - Tue, Apr 21
United Airlines Logo
1:25 pm - 9:19 pm
DEN
-
YXU
5h 54m
1 stop
United Airlines Logo
5:10 am - 7:40 pm
YXU
-
DEN
16h 30m
2 stops
$654United Airlines
Tue, Apr 14 - Tue, Apr 21
United Airlines Logo
5:15 am - 9:19 pm
DEN
-
YXU
14h 04m
2 stops
United Airlines Logo
5:10 am - 7:40 pm
YXU
-
DEN
16h 30m
2 stops
$664United Airlines
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 $461 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 $461.

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 $686, 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 March, when tickets cost $404 (return) on average. On the other hand, the most expensive months are January and December, when the average cost of round-trip tickets is $620 and $567 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 52% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 19 weeks before departure.

Good to know

Low seasonNovember
Cheapest flight$105
Best time to beat the crowds but there is an average 2% increase in price.
Most popular time to fly and prices are also 11% 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.

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

    The cheapest time of day to fly to Ontario is generally in the afternoon, when round-trip flights cost $671 on average. Morning departures are around 8% 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 $729.

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 8242 reviews
8.5Crew
7.8Entertainment
8.1Boarding
7.9Comfort
7.2Food
Airline reviews

I was happy that I was able to get a last minute flight but unfortunately my seat was a middle seat. Even with Delta Comfort I wasn't comfortable

8.0 ExcellentSheila, Mar 2026
ATL - EWR
Read more Delta reviews

I was happy that I was able to get a last minute flight but unfortunately my seat was a middle seat. Even with Delta Comfort I wasn't comfortable

There’s not much to say about a one hour flight. This is a connection from LA to RNO that I missed the previous night due to a mechanical check delay on my originating flight from JFK to LAX. The short flight itself was fine. Instructions from the pilot and crew were per usual. The coffee was barely lukewarm, which possibly was purposeful so we would down it quickly. Bags were already on carousel upon reaching baggage claim, which was excellent.

Flight was warm for first few hours and quite rough

Seat was extremely hard which made even a short 1 hour 20 minute flight fairly uncomfortable.

Everything was good except wifi and a leaking drink chiller. The floor was all wet and my bag was soaked. Did not notice until debarking. Have not heard back from Delta. Even though this was leg one of an international flight in first class, they denied access to their Sky Club - very disappointing!

The staff was fine. The plane was extremely tight, and I paid for the wifi and it did not work at all. I was actually going to ask for a refund.

two hour delay and the Delta representative on the PA system was unable to understand

An awesome flight crew. FC seat cushion just doesn’t cut it for a 3+ hour flight.

2+hrs delay without any reason provided and a cramped flight

We waited an hour on the runway to get a gate in Orlando

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!

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.

Super experience. Earlier than schedule departure and arrival. Baggage handling was very good

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

Information on your arrival and departure airports