$113 Find Cheap Flights from Colorado to Ontario

1 adult
1 adult, Economy

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Low seasonJanuary
High seasonJuly
Cheapest flight$113
Best time to beat the crowds but there is an average 15% increase in price.
Most popular time to fly and prices are also 4% lower on average.
Flight from Denver to Montreal

FAQs for booking flights from Colorado to Ontario

  • How does KAYAK find such low prices on flights from Colorado 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 Colorado to Ontario.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Colorado 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 Colorado 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 Colorado 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 Colorado 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 Colorado to Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which is the cheapest airport to fly into in Ontario?

    Prices will differ depending on the departure airport, but generally, the cheapest airport to fly to in Ontario is Toronto Pearson Intl Airport (YYZ), with an average flight price of $363.

  • What is the cheapest day to fly to Ontario?

    Based on KAYAK data, the cheapest day to fly to Ontario is Thursday where round-trip tickets can be as cheap as $692. On the other hand, the most expensive day to fly is Monday, where round-trip prices are $815 on average.

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

    The cheapest time of day to fly to Ontario is generally at night, when round-trip flights cost $588 on average. Morning departures are around 7% 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.

  • What is the cheapest flight to Ontario?

    The cheapest ticket to Ontario from Colorado found in the last 72 hours was to Toronto Pearson Intl Airport, at $369 round-trip. The most popular route is 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 $369.

  • What is the cheapest month to fly from Colorado to Ontario?

    The cheapest month for flights from Colorado to Ontario is February, when tickets cost $338 (return) on average. On the other hand, the most expensive months are April and May, when the average cost of round-trip tickets is $542 and $541 respectively.

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

    To get a below average price on the flight from Colorado to Ontario, you should book around 3 weeks before departure. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

  • How long is the flight to Ontario?

    An average nonstop flight from Colorado to Ontario takes 10h 51m, covering a distance of 1422 miles. The shortest route is Denver (DEN) to Toronto Pearson Intl Airport (YYZ) with an average flight time of 3h 05m.

  • What are the most popular destinations in Ontario?

    Based on KAYAK flight searches, the most popular destination is Toronto (92% of total searches to Ontario). The next most popular destinations are Ottawa (6%) and London (2%). Searches for flights to Thunder Bay (1%) and to Kingston (0%) are also popular.

Reviews of the top 4 airlines serving from Colorado to Ontario

 
Need help choosing which airline to fly with from Colorado 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.
8.0
DeltaOverall score based on 7952 reviews
7.3Food
7.9Comfort
8.2Boarding
7.9Entertainment
8.5Crew
Airline reviews

Very late arrival at PWM. Late jet getting to ATL. Equipment problem with aircraft - could not get enough water onto plane., Another delay getting FAA approval for flight with bottled H2O. Not the crew’s problem.

4.0 OkayJames, Jul 2025MSN - ATL
Read more Delta reviews

Very late arrival at PWM. Late jet getting to ATL. Equipment problem with aircraft - could not get enough water onto plane., Another delay getting FAA approval for flight with bottled H2O. Not the crew’s problem.

Everything was fine except the entertainment was not working for half of the flight.

Easy boarding with an extremely kind attendant. Seats were spacious and we had 3 seats for 2 people so we could stretch out. Comfortable air flow and very attentive and hospital attendants. Bathrooms and food were the only negative. Bathrooms were so small you could hardly get in and close the door. I don’t think an obese person would fit or a person with a movement disability. Food was the trending food for flights, nonexistent. We spent $40 getting sandwich and snack at airport for our 6 hour flught.

At first, we were on the runway for about an hour, literally. The Captain did explain that the Control Tower just had a change shift (sounds like an unrealistic excuse) and then that we had to change a runway. A regular economy seat is made for 12 yo twiggy. I understand Delta wants to push for an upgrade, but after sitting in a Comfort seat and in First class. I would say First class is not worthy of my money. The landing was delayed because of the weather in NYC, I don't hold that against Delta, of course. The Captain did alert us to that upon takeoff in Vegas and again as we reached NY.

No one fussed at me about my pap machine as a 3rd pice on the plane. Boarding was pleasant and smooth. The boarding agent in Anchorage was a fun character- he could be in a movie. :~) The on-board crew were downright pleasant. No militant attitudes on Delta. Like all planes these days the seats are too narrow for standard Americans and at 5’2” there is barely enough leg room. I don’t know how tall people fold themselves into the seats. But that’s nothing specific to Delta

Great. Very smooth. Plenty of information. However, wish they would give out a menu in advance of making a dinner choice like other international airlines. The flight attendant says chicken or pasta and there are details about ingredients or spices requiring the passenger to ask which requires the flight attendant to answer many times. So easy to solve this problem. P

I'm a tall guy and even the seats with more leg room were not as comfortable as I had hoped.

My husband upgraded our seats and I don't know if it was due to the type of planet was or if they didn't upgrade our seats. We were supposed to be in I believe comfort seats and they were just as tight as any other seat- no leg room and we are very tall people but at least it wasn't extremely cold. My husband did put in a complaint about our seating because he paid extra and if we would have known that the space and the tightness would have been the same, we just would have gotten the emergency row emergency row seats that we normally get. We love Delta but both our flights coming home we're not good. Oh I forgot to mention that on our flight to Hawaii our luggage wheels got broke and we had to purse new luggage on vacation then we never had this problem so we didn't know protocol and reported it after we got home only for them to tell is we only had 24hrs to report the damage. Not sure what was going on with Delta this vacation trip.

My flight was extremely cold. I had a jacket and a cover was left in each seat. The cover was extremely thin and I have a disability, fibromyalgia and arthrithis and AC air is the worst. I closed my vent and my husbands vent and it still was frigid. I asked the attendant if I could get another cover and she quickly almost dismissively and totally unconcerned stating, (I quote) (one per chair) and walked off so quickly that I didn't get a chance to explain to her that I literally have adisability. I didnt want to make a seen so I set on that flight for over 5 hours in pain, joints locking up and extremely uncomfortable. When my fibromyalgia flares up my joints not only ache but they will lock up also and it takes me days to get back to my regular self even though I take medication for it. I felt like it would not have hurt anyone at all for her to just give me an extra cover because I'm sure they have all types of medical issues in people that fly every day.

After all the weather issues at least they got me to my destination the next day

Flight was actually on Air Canada. The flight itself was fine. Nothing special. Food was pretty pathetic except for cookies. They offered plenty of food and drinks but just wasn't very good. Even for airline food.

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

Great experience…left a bit behind schedule but made up fir that in the air and landed 10 minutes early 😁

The seat and leg room was not good. The food and beverage service was good.

For economy, it was very good. Staff was great, they even let some of us change seats for more leg room... Put an empty seat between us which was fantastic for a 12hr flight. Onboard entertainment was excellent, I think over 200 choices of movies/tv/etc The bad was the barely/nonfunctional wifi that cost either $16.99 or 1700 miles (full flight). It was atrocious... Definitely the worst of the last 3 long haul major airlines I was on the last few months.

Electric plugs didn't work. Entertainment system wasn't working

The design of the light switch on the arm rest is ridiculous.

The gate attendant let me walk right by her with a bag too big for the overhead compartment

I do prefer to fly United and have always had excellent service, except for bad weather. Flights are on time and staff is alway curtious and helpful

We were delayed in Toronto on the tarmac for THREE hours with no clear indication as to why except that it was not a safety hazard. Pilot did apologize more than once but even he was unable to explain why exactly we were delayed. I overheard the stewards saying that the captain was very frustrated with the situation as well because he was not able to explain why except it had something to do with water supply or system on the aircraft and now we needed to wait for an engineer to approve the aircraft for flight. It was very frustrating and distressing as a passenger and we should have been given complimentary meals at the very least.

Crew was nice especially by North American standards. Bad good. No entertainment screens. Terrible WiFi

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!

Not only was the flight delayed more than 3 hours but also there was no internet or movies on the flight. It was Flair/Spirit quality of experience at Westjet prices

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.

It was good, flight was on time, boarding was smooth and done in zones, food was good too but there was no form of entertainment. Luggage’s were intact. So an overall good flight

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.

No access to any entertainment No food other than a cookie or pretzels even tho flight was over the supper hour Seats very close together and very little leg room Staff was very good

The cancelation of my flight from Toronto to Edmonton without any solution given to me for my next flight. Very poor connection from Toronto to Edmonton

Flight was delayed by 1.5hrs. Once inside, people had their small handbags on the storage. The crew (male guy) was not helpful in making some space in the storage. Instead, he asked few bags to be checked-in and it was not a great experience. No attempt to help but just followed the things with a straight face. People had their literally small bags and he wouldnt not move from one storage to another even if there was space and would not let us do i as well. Once flight was on, they ran out of Orange juice, really running out of orange juice when the temp were 32.degrees outside. didnt made the sense. Onasking for a extra snack, he made a face as if he was giving me out of his pocket. if the flight was delayed, there could have an attempt to provide something extra incase people did asked.

Our flight was canceled at the last minute. Someone on the flight said the exact same thing happened to her the day before. I will say they helped us book a flight on another airline so that we could still make our vacation with little delay.

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

Abandoned me in hallway in a wheelchair… which I asked for because I sprained my back. After waiting in the hallway, I decided to walk the rest of the way since someone respecting me up.. My experience with the united was totally the opposite. Wheelchair access, propped swift and save me a lot of grief. Air Canada totally disorganized.

Bad experience boarding and flight got delayed didn’t make it to my next flight

The food on the trip Toronto to Athens could be better: the chicken didn’t taste good.

Conflicting information provided about baggage allowance. One screen said I had a carry on and another said I didnt.

Flight was delayed but the real issue is how long we sat after boarding. Space very limited for an overnight flight and seatbacks didn’t recline so it was almost impossible to sleep.

The staff made sure I was comfortable, moved me to a better seat with more leg room

Somehow, my booking was under my preferred name instead of my legal name so they almost didn’t let me board the plane at LAX. This problem should have been notified to me when I was still in Toronto.

Book cheap flights from Colorado to Ontario

Recent round-trip flight deals

9/12Fri
1 stop
5h 34mDEN-YTZ
9/15Mon
1 stop
12h 56mYTZ-DEN
$279
8/2Sat
1 stop
16h 54mDEN-YTZ
8/9Sat
1 stop
10h 38mYTZ-DEN
$287
9/7Sun
1 stopWestJet
8h 32mDEN-YYZ
9/13Sat
1 stopWestJet
14h 59mYYZ-DEN
$291
9/18Thu
1 stopWestJet
8h 37mDEN-YYZ
9/21Sun
1 stopWestJet
14h 59mYYZ-DEN
$298
7/31Thu
nonstopAir Canada
3h 46mDEN-YUL
8/6Wed
nonstopAir Canada
4h 16mYUL-DEN
$305
8/2Sat
1 stopAir Canada
11h 14mDEN-YOW
8/8Fri
1 stopAir Canada
6h 21mYOW-DEN
$310
8/7Thu
1 stopUnited Airlines
9h 26mDEN-YUL
8/14Thu
1 stopUnited Airlines
7h 01mYUL-DEN
$368
7/26Sat
1 stopUnited Airlines
8h 40mDEN-YOW
7/26Sat
1 stopUnited Airlines
7h 01mYOW-DEN
$369
8/3Sun
1 stopDelta
8h 42mDEN-YUL
8/12Tue
1 stopDelta
8h 27mYUL-DEN
$406
8/2Sat
2 stopsDelta
15h 08mCOS-YUL
8/9Sat
1 stopDelta
5h 39mYUL-COS
$413

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Recent one-way flight deals

9/19Fri
2 stops
7h 47mDEN-YUL
$113
9/16Tue
1 stopWestJet
8h 37mDEN-YYZ
$118
9/11Thu
1 stopAmerican Airlines
16h 08mDEN-YUL
$144
8/14Thu
nonstopAir Canada
3h 46mDEN-YUL
$145
8/14Thu
1 stopAmerican Airlines
16h 04mDEN-YUL
$146
8/2Sat
nonstopAir Canada
3h 46mDEN-YUL
$153
8/27Wed
1 stopDelta
10h 05mCOS-YUL
$154
8/27Wed
2 stopsDelta
9h 57mCOS-YUL
$160
7/25Fri
1 stopUnited Airlines
7h 07mDEN-YOW
$161
9/10Wed
1 stopUnited Airlines
7h 59mDEN-YOW
$166

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Last minute flights from Colorado to Ontario

Last minute flight, train and bus deals

7/15Tue
multi-stopWestJet
10h 26mDEN-YOW
7/20Sun
multi-stopWestJet
18h 12mYOW-DEN
$358
7/15Tue
multi-stopAir Canada
11h 14mDEN-YOW
7/23Wed
multi-stopAir Canada
6h 21mYOW-DEN
$362
7/15Tue
multi-stopWestJet
10h 26mDEN-YOW
7/20Sun
multi-stopWestJet
20h 12mYOW-DEN
$363
7/15Tue
multi-stopAir Canada
11h 14mDEN-YOW
7/24Thu
multi-stopAir Canada
7h 05mYOW-DEN
$368
7/15Tue
multi-stopUnited Airlines
7h 17mDEN-YOW
7/19Sat
multi-stopUnited Airlines
15h 18mYOW-DEN
$376
7/15Tue
multi-stopUnited Airlines
11h 16mDEN-YOW
7/18Fri
multi-stopUnited Airlines
7h 07mYOW-DEN
$463
7/14Mon
multi-stopDelta
7h 20mDEN-YYZ
7/21Mon
multi-stopDelta
7h 55mYYZ-DEN
$466
7/14Mon
multi-stopDelta
8h 42mDEN-YUL
7/22Tue
multi-stopDelta
11h 43mYUL-DEN
$525
7/15Tue
multi-stopAmerican Airlines
12h 22mDEN-YUL
7/22Tue
multi-stopAmerican Airlines
6h 12mYUL-DEN
$535
7/15Tue
multi-stopAmerican Airlines
12h 22mDEN-YUL
7/22Tue
multi-stopAmerican Airlines
9h 14mYUL-DEN
$540

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Everything you need to know for your flight to Ontario

Cabin class types available on flights to Colorado

Cabin classes available on flights to Colorado. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.

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