$137 Find Cheap Flights from Denver to Ontario - Compare and Save

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 9/27. 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

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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$437
Ottawa
Ottawa1 stop$469
London
London1 stop$399
Toronto
Toronto1 stop$437
Ottawa
Ottawa1 stop$469
London
London1 stop$399

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

Sat, Sep 5 - Sat, Sep 12
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
8:00 pm - 11:20 am
YUL
-
DEN
17h 20m
1 stop
$363WestJet
Thu, Sep 17 - Sun, Sep 20
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
7:15 am - 11:20 am
YUL
-
DEN
30h 05m
1 stop
$379WestJet
Thu, Sep 17 - Sun, Sep 20
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
7:15 am - 11:20 am
YUL
-
DEN
30h 05m
1 stop
$385WestJet
Wed, Aug 26 - Mon, Aug 31
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
8:00 pm - 11:20 am
YUL
-
DEN
17h 20m
1 stop
$386WestJet
Tue, Aug 11 - Tue, Aug 18
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
8:00 pm - 11:20 am
YUL
-
DEN
17h 20m
1 stop
$388WestJet
Mon, Aug 17 - Wed, Aug 19
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
8:00 pm - 11:20 am
YUL
-
DEN
17h 20m
1 stop
$389WestJet
Tue, Sep 1 - Sat, Sep 5
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
8:00 pm - 11:20 am
YUL
-
DEN
17h 20m
1 stop
$391WestJet
Wed, Aug 12 - Tue, Aug 18
WestJet Logo
12:15 pm - 11:45 pm
DEN
-
YUL
9h 30m
1 stop
WestJet Logo
8:00 pm - 11:20 am
YUL
-
DEN
17h 20m
1 stop
$392WestJet
Mon, Aug 3 - Fri, Aug 7
Multiple Airlines Logo
8:52 pm - 8:50 pm
DEN
-
YYZ
21h 58m
1 stop
Multiple Airlines Logo
8:35 pm - 5:21 pm
YYZ
-
DEN
22h 46m
2 stops
$437Multiple Airlines
Fri, Aug 14 - Mon, Aug 17
Multiple Airlines Logo
5:05 pm - 1:00 pm
DEN
-
YTZ
17h 55m
1 stop
Multiple Airlines Logo
8:55 am - 11:57 pm
YTZ
-
DEN
17h 02m
1 stop
$438Multiple 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.

How much is a round-trip flight from Denver to Region of Ontario?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Denver to Region of Ontario departing in August.

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 5 days was to Toronto, at $429 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 5 days was $429.

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 $705 on average. Morning departures are around 4% cheaper than evening flights, on average. The most expensive time of day to fly to Ontario is generally in the evening, which is peak travel time and where the average cost of a ticket is $793.

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 $625, 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 January, when tickets cost $129 (return) on average. On the other hand, the most expensive months are May and June, when the average cost of round-trip tickets is $244 and $236 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, Thursday is the cheapest day to fly and Sunday 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 56% 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$137
Best time to beat the crowds with an average 21% drop in price.
Most popular time to fly and prices are also 25% 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 3 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.
7.4
United AirlinesOverall score based on 9953 reviews
8.1Crew
7.1Entertainment
7.3Comfort
6.7Food
7.7Boarding
Airline reviews

The entertainment they offer could use some games, and maybe they could add some cookies to the snack menu. And the automated messages are a bit repetitive. But it was comfortable temperature wise and the seats were comfortable. The crew is very polite and helpful

6.0 GoodAnonymous, Jun 2026
DEN - YEG
Read more United Airlines reviews

The entertainment they offer could use some games, and maybe they could add some cookies to the snack menu. And the automated messages are a bit repetitive. But it was comfortable temperature wise and the seats were comfortable. The crew is very polite and helpful

Putting people that close to the bathroom, where you have to look into the bathroom as people are exiting and entering was not great and the smell was also not great. I know the airlines are desperate for more chairs, but that seat is a crime.

one staffer was frustrated (it happen); the flight was late and the pilot mentioned they'll make amend but the snacks were the same, other than that the aircraft was clean and everything went smooth, no complaints

ticket agent lady wás very helpful , she arranged wheel chair for my elderly mother

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.

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

Overall good flight. The pilots were excellent. It was a nice flight, but the seats were a little uncomfortable.

The free snack options are pretty pitiful for a 2.40h flight.

Not worth the premium paid for the first class ticket

Fine. Though no food or entertainment so the survey needs to be updated with those options.

Westjet was late and we missed our connecting flight with Cathay. Had to wait 8 hours. Westjet only allows 1 checked in baggage for international flights- it’s always been 2. Canada allows only 1 sandwhich bag size full off small liquids. Everything else will be tossed. Awful trip. Will never fly west jet or go to Toronto to connect flights!

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

West Jet flight was cancelled and I was not notified. I found out when I tried to check in on-line. Spent 4 hours on the phone with West Jet and Just Fly trying to figure what happened.

Only issue was checking in took over an hour and was very stressful. It all worked out, but we weren't sure for a while.

Flight was delayed 3 times. Then cancelled due to pilot being timed out. They refused hotel vouchers. Gate attendants were very rude and could not help you at all.

Flight was on time. Online check in capabilities made things quick and easy. Zone boarding was enforced, which I appreciate. Everyone was not lining up ahead of their zone being called. Crew was professional and friendly.

The big lady was sitting right next to me and the button to recline my seat was blocked by her huge arm. No power outlet for chargers. No inflight Wi-Fi movies

Trip was uneventful which is good. Boarding took a long time due to many disabled/elderly requiring assistance which again is fine. Landing and take off were excellent. Food and entertainment were as expected, bring your own if you have preferences otherwise you get what you get.

Okay but not like typical first or business class. On domestic airlines

I liked the kindness of the check in counter crew, the flexibility with changing seats and the comfort. Better free drink selection would have been good but it wasn't a long flight.

We had a very long delay. First the inbound flight took a while, then maintenance, they “fixed it” to then do boarding and leave the gate, and waste a lot of time to have to go back to the gate and eventually deplane. Had to wait for a new aircraft, wait for a gate, and do the whole thing again. Instead of leaving at 9:50am we left until past 1. I could’ve not woken up at 5am, or spend some more time with my family if they gave more grace period of time between flights to give some time in case of any issues. But they have to make all and every dollar possible

Most expensive flight… and they are trying to pinch more and more money out of you. Baggage, snacks, pillows, headphones… — so many airlines do far better than this… surely a national airline can do better?

Air Canada should allow basic economy passengers to upgrade if they wish to do so.

My second flight ended up being through United and it was fine. Again, just frustrating that it was so late.

I had written all my complaints on my trip from Grand Junction to Denver so I will repeat it here! I was absolutely appalled that I had to pay for a regular seat that I choose 24 hrs before boarding! Also I checked my large bag which I had to pay for as well, and by the time I boarded all the room in the bins were gone so also had to check that one. I noticed people pulling out oversized suitcases, bigger than the measurements stated for carry on, and also large pack packs stuffed full! So these people were taking up 2 or 3 spaces that the rest of us should have been able to use but couldn’t! NoTV on the flight! Thankfully I had downloaded the United Airlines app and was able to watch movies on my phone. Don’t remember the last time I flew in a plane with no movie screens!

My flying experience with Air Canada was good but the wheelchair situation wasn't good at all and if would be good to make sure that they have the appropriate services available for your traveling passengers.

Air Canada flights offer excellent service. This flight from DEN to YYZ in an Airbus A220-300 was so sooth it was almost like spending a couple of hours reading a good book, except for the cabin crew who provide friendly, thoughtful service throughout the flight. Kudos to AC pilots, cabin crew and management. I’ve now added Airbus 220.300 to my preferred list if planes to fly in.

Lots of delay! Cheotic and disorganized! Aircraft had technical problem and was stopped and returbed to the gate while taking off! . United States is sinking under Joe Biden!

Ops was very poor. 2 of 2 legs were both late. Air Canada changed our seats 3x and my friend and I never did get to sit together. Flight attendant opened the lavatory on me and was not professional about it. Food was blah. The worst part is that the flight was so late from Toronto that we missed our connection in Athens. We lost out on other airline tickets and nobody even said sorry or tried to help. Our return flight was cancelled and my friend and I are rebooked on completely different flights next week.

Legroom was not good and can be improved and food needs upgrade.

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

Information on your arrival and departure airports