$103 Find Cheap Flights from Colorado to Ontario

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Low seasonJanuary
High seasonJuly
Cheapest flight$103
Best time to beat the crowds with an average 2% drop in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from Denver to Toronto Pearson Airport

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 $335.

  • 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 $697. On the other hand, the most expensive day to fly is Monday, where round-trip prices are $786 on average.

  • 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 $243 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 $732.

  • 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 $296 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 $296.

  • 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 $289 (return) on average. On the other hand, the most expensive months are August and April, when the average cost of round-trip tickets is $566 and $542 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 9h 53m, 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 10m.

  • What are the most popular destinations in Ontario?

    Based on KAYAK flight searches, the most popular destination is Toronto (93% of total searches to Ontario). The next most popular destinations are Ottawa (5%) and London (2%). Searches for flights to Thunder Bay (0%) and to Kingston (0%) are also popular.

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 7941 reviews
7.9Comfort
7.3Food
8.5Crew
7.9Entertainment
8.2Boarding
Airline reviews

737-800 in first class was pretty dumpy. Seat had an uncomfortable angle, storage under the seat was blocked so even my very modest backpack didn't fit, power outlet was flaky. Weird tiny seat pockets that couldn't hold a gallon ziploc bag, emesis bag missing, etc. etc. No in-flight service due to turbulence. Crew was excellent, boarding was smooth despite a full flight.

6.0 GoodWalter, May 2025ONT - SLC
Read more Delta reviews

737-800 in first class was pretty dumpy. Seat had an uncomfortable angle, storage under the seat was blocked so even my very modest backpack didn't fit, power outlet was flaky. Weird tiny seat pockets that couldn't hold a gallon ziploc bag, emesis bag missing, etc. etc. No in-flight service due to turbulence. Crew was excellent, boarding was smooth despite a full flight.

Food from the flight from Atlanta to Santiago was very poor..

Flight was delayed due to weather. Crew did a nice job of making us comfortable. No complain complaints.

Our bag was lost so that made unnecessary chaos On our trip

Delta is my preferred airline. I've traveled with them for years. On time in most cases, good communication, easy to use app. Most planes are pretty nice. I was on a CRJ 700/900 however, which was pretty badly aged inside and needed a refresh. No infotainment, unreliable wifi, best to download before boarding or bring a book. Food choices are really just snacks on this flight, nice variety but about what you'd expect. Great staff and prompt in departure and early arrival too. Overall quite satisfied.

Crew was friendly Love the entertainment in the seat head rest.

Delta flight was on time, seats were comfortable, and crew was nice.

This had nothing to do with Delta… The flights were on time and flawless. The service was excellent. We purchased seats in (aisle/middle) comfort plus since this was a cross country flight. Unfortunately, the woman seated at the window was 300+ pounds and, as might be expected, covered up about a third of the middle seat also. there was absolutely nothing that Delta could have done about that… I just don’t know what the answer should be. If you purchase a seat, you should should be able to use the entire seat and not just the portion that someone else is not sitting/oozing in. Disappointing…there should be something that could be done….I'm just not sure what solution could be.

Delayed take-off. Very small plane so very scary with lots of bumps during the flight. Would never fly Delta on short flights in small 80 seaters plane again! Felt relieved when landed.

The worst part was I was NOT allowed in the lounge even though I was holding a first class ticket and have a premium American Express card. I have flown Business or First Class with many airlines. Delta is the ONLY one who does not extend this courtesy to anyone except people who hold the very expensive American Express card. As a result, I won’t fly Delta if I have any other choice.

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.

Overall poor for me I paid extra for seats with leg room and my regional flights exit row seats have less leg room then the others that's money that could have been saved and on my final flight home the flights air was not operating it was unbearably hot in the cabin I will be contacting United and filing a DOT complaint

All male crew was just too woke for me. I felt like a sardine. I will never take a window seat or the rearmost seat again. I booked early and did not pay for seat selection and that was a mistake. The security at IAH was atrocious. I was violated and radiated as I was in a hurry to connect to my other flight. I may have lost items under the seat in front of me that I couldn't see nor bend over to look.

I don’t understand the purpose of the orange “priority” tag on my bag. This tagged, my bag is last or near to the last bag to come down the carousel at IAH.

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

The staff were the friendliest I have encountered in years. Absolutely great!

Plane changed to one with no entertainment system or ability to serve hot meals

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

Good. Would be better if the carry on baggage was free.

Horrible. I checked out myself that it seems that I can have a free carry-on. But they ask me to pay $75 when we are nearly boarding. It was tricky during check out that make you mistake that you can have a carry-on beside your personal item. Also they ask $75 in the airport instead of $35 during checkout. So the whole process is designed to make you this mistake

Westjet is one of the worst airlines in the world. 100% guaranteed to have flight delays and flight cancellations. Will never book again with Westjet.

Plane should have entertainment, instead of people paying to use wifi

Westjet has been absolutely terrible! Flights continually cancelled. Took 4 days to get home. Would have been 5, but we booked last flight with another airline after our Westjet flight was cancelled. Even pilot on original flight looked frustrated! Funny how they say cancelation is weather related, but they still have more than 1 other flight leaving to same destination on same day, but of course those are all full. This happened more than once on this trip. Two weather related cancelations and 1 mechanical. Not sure if the last flight even went ahead. Felt so sorry for families with kids and babies, and the older travellers. Felt like we lived out of suitcases and airports for days - SO RIDICULOUS! Next to no help from Westjet staff at airports, but it appears there is nothing they can help you with. Westjet has made it that they are unreachable when you need them! People were getting extremely frustrated, and rightfully so. Additional costs to us really added up, but Westjet literally DOESN'T CARE! Final straw was when we had to pay $1280 on a different airline (economy) trying to get home after another cancelled flight. Westjet will be refunding us a whole $140! Can't believe how this airline operates. We will never, ever use them again!

2.5 hour delay sitting in the plane on the tarmac, you tell me how the experience was

I hope these comments will find their way to AC customer experience team. Me and my spouse 50 years of aged coming back from 7 days perfect vacation... While boarding in FLL flight AC1621, one of the boarding agents (tall aged african american) man literelly yeld at my wife during the picture talking process. MAM ! STEP !! BACK !!! We are not illegal immegrants beying deported, nor are we in the millitary. We are customers returning home. This was unacceptable. While boarding in YYZ flight AC1154, one of the boarding agents (tall aged caucasian) man criticied with several complesant remarks my passport condition saying that I could not travel intl with it due to stain, decoloration, and BLOOD. My passport does not have blood on it! Yes it might be in less than perfect condition, but their are ways to talk to customer that does not imply not allow a boarding agent to be angry fathery like, or a custom agent looking at a suspicious individual. Both experience were less than acceptable for might I remind you a paying CUSTOMER returning home.

This flight didn't happen for me because of overbooking.

Terrible experience, flight was delayed both ways. Limited compensation for the 5+ hour delay. Will not be flying Air Canada Rouge, and don’t recommend you do either.

The boarding was relatively quick, the crew welcoming and flight uneventful. The omission of meals on all airlines is unacceptable especially when the flight is during a mealtime such as this one, (lunchtime), is unacceptable.

Everything was simple and easy. The lady at the gate was super friendly, I wish I had her name to share. She's a little older, dark-haired. You can tell she likes her job and would be a great influence on any young people training with her.

No Charging ports for personal electronics, which were required to use wifi entertainment.

Rushed, the boarding was a great deal like a Chinese fire drill.

it was red eye flight, it was ok, there was beverage service, thats it i didnt care much as i wanted to sleep

Everything went smoothly. I appreciate the selection of free movies.

Book cheap flights from Colorado to Ontario

Recent round-trip flight deals

5/28Wed
2 stopsWestJet
10h 20mDEN-YYZ
5/30Fri
1 stopWestJet
15h 02mYYZ-DEN
$267
8/22Fri
1 stopWestJet
10h 26mDEN-YHM
8/31Sun
1 stopWestJet
14h 52mYHM-DEN
$273
6/4Wed
1 stop
10h 09mDEN-YYZ
6/11Wed
2 stops
18h 01mYYZ-DEN
$301
5/29Thu
1 stop
9h 14mDEN-YYZ
6/2Mon
1 stop
26h 03mYYZ-DEN
$305
7/24Thu
1 stopDelta
7h 33mCOS-YUL
8/4Mon
1 stopDelta
5h 39mYUL-COS
$486
8/11Mon
nonstopAir Canada
3h 46mDEN-YUL
8/25Mon
nonstopAir Canada
4h 16mYUL-DEN
$489
7/24Thu
2 stopsDelta
15h 08mCOS-YUL
8/4Mon
1 stopDelta
8h 27mYUL-COS
$495
5/31Sat
1 stopAir Canada
9h 51mDEN-YUL
6/7Sat
1 stopAir Canada
10h 34mYUL-DEN
$511
10/9Thu
1 stopUnited Airlines
9h 26mDEN-YUL
10/14Tue
1 stopUnited Airlines
15h 39mYUL-DEN
$639
5/19Mon
2 stopsUnited Airlines
24h 28mDEN-YXU
5/23Fri
2 stopsUnited Airlines
15h 25mYXU-DEN
$729

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Recent one-way flight deals

6/24Tue
2 stopsWestJet
10h 18mDEN-YYZ
$103
6/23Mon
2 stopsWestJet
10h 18mDEN-YYZ
$107
7/8Tue
3 stops
23h 38mDEN-YYZ
$134
7/9Wed
1 stop
22h 49mDEN-YYZ
$142
6/10Tue
1 stopAir Canada
9h 51mDEN-YUL
$218
6/9Mon
1 stopDelta
12h 40mDEN-YUL
$225
5/25Sun
nonstopAir Canada
3h 15mDEN-YYZ
$247
6/18Wed
1 stopDelta
6h 26mDEN-YYZ
$257
6/9Mon
1 stopUnited Airlines
14h 55mDEN-YUL
$262
6/8Sun
nonstopUnited Airlines
3h 10mDEN-YYZ
$285

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Last minute flights from Colorado to Ontario

Last minute flight, train and bus deals

5/6Tue
multi-stop
30h 00mDEN-YYZ
5/10Sat
multi-stop
14h 42mYYZ-DEN
$579
5/9Fri
multi-stop
11h 40mDEN-YYZ
5/11Sun
multi-stop
17h 09mYYZ-DEN
$618
5/9Fri
multi-stopDelta
9h 54mDEN-YYZ
5/12Mon
multi-stopDelta
10h 29mYYZ-DEN
$834
5/9Fri
multi-stopDelta
9h 29mDEN-YYZ
5/12Mon
multi-stopDelta
11h 03mYYZ-DEN
$884
5/9Fri
nonstopUnited Airlines
3h 12mDEN-YYZ
5/12Mon
multi-stopUnited Airlines
10h 42mYYZ-DEN
$1,045
5/6Tue
multi-stopUnited Airlines
14h 45mDEN-YUL
5/16Fri
multi-stopUnited Airlines
17h 01mYUL-DEN
$1,058
5/9Fri
nonstopAir Canada
3h 11mDEN-YYZ
5/12Mon
nonstopAir Canada
3h 45mYYZ-DEN
$1,229
5/6Tue
nonstopAir Canada
3h 11mDEN-YYZ
5/8Thu
nonstopAir Canada
3h 45mYYZ-DEN
$1,277
5/6Tue
multi-stopWestJet
34h 22mDEN-YUL
5/16Fri
multi-stopWestJet
19h 57mYUL-DEN
$1,284
5/9Fri
multi-stopWestJet
10h 31mDEN-YKF
5/11Sun
multi-stopWestJet
13h 50mYKF-DEN
$2,255

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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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