$124 Find Cheap Flights from Colorado 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 Colorado to Ontario departing on 7/18. 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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Good to know

Low seasonFebruary
Cheapest flight$124
Best time to beat the crowds with an average 11% drop in price.
Most popular time to fly and prices are also 2% 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 airlines fly most frequently to Ontario?

    Air Canada connects Colorado to Ontario with 30 flights per week. United Airlines also offers 30 flights per week, while Austrian Airlines follows with 7 flights per week.

  • How many airports are there in Ontario?

    There are 24 airports in Ontario. The busiest airport is Toronto Pearson Airport (YYZ), with 78% of all flights arriving there.

  • 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 $379.

  • 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 $680. On the other hand, the most expensive day to fly is Sunday, where round-trip prices are $814 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 $702 on average. Morning departures are around 5% 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 $790.

  • What is the cheapest flight to Ontario?

    The cheapest ticket to Ontario from Colorado found in the last 5 days was to Toronto Pearson Intl Airport, at $427 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 5 days was $427.

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

    The cheapest month for flights from Colorado to Ontario is June, when tickets cost $93 (return) on average. On the other hand, the most expensive months are April and January, when the average cost of round-trip tickets is $252 and $198 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 4 weeks before departure, which saves you about 55% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 7 weeks before departure.

  • How many cities have direct flights to Ontario?

    From Colorado, there are direct flights to Ontario from 1 city. This city is Denver and there are 71 direct flights each week.

  • How many direct flights to Ontario are there each day?

    There are around 11 direct flights from within Colorado to Ontario every day. Most flights (61%) depart in the morning.

  • How many direct flights to Ontario are there each week?

    Each week there are around 71 direct flights from within Colorado to Ontario. The most common day for departures is Sunday, with 17% of flights taking off on this day.

  • How long is the flight to Ontario?

    An average nonstop flight from Colorado to Ontario takes 9h 56m, 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.

  • How many long-haul flights are there to Ontario each week?

    There are not any long-haul (6-12 hour flight duration) or medium-haul (3-6 hour flight duration) flights to Ontario. Instead, there are 71 short-haul flights (up to 3 hour flight duration), with the most arriving from Denver.

  • What are the most popular destinations in Ontario?

    Based on KAYAK flight searches, the most popular destination is Toronto (95% of total searches to Ontario). The next most popular destinations are Ottawa (4%) and London (1%). Searches for flights to Thunder Bay (0%) 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.
7.8
DeltaOverall score based on 8430 reviews
7.8Comfort
8.5Crew
7.2Food
8.1Boarding
7.8Entertainment
Airline reviews

Not really a “Delta” problem but worth mentioning: Boarding was a difficult process. TSA seemed understaffed and Pre-Check took longer than regular TSA. The supervisor was frazzled and yelled at travelers. Once through TSA, we had to put our carry-ons through another x-ray machine. Then queue up to board with both boarding pass and ID. Then, when we got to the stairs on the tarmac, we had to show our boarding pass again. Maybe this is just normal for Kona since the terminal is outdoors (but still a “secured” area).

6.0 GoodMary, Jun 2026
KOA - SEA
Read more Delta reviews

Not really a “Delta” problem but worth mentioning: Boarding was a difficult process. TSA seemed understaffed and Pre-Check took longer than regular TSA. The supervisor was frazzled and yelled at travelers. Once through TSA, we had to put our carry-ons through another x-ray machine. Then queue up to board with both boarding pass and ID. Then, when we got to the stairs on the tarmac, we had to show our boarding pass again. Maybe this is just normal for Kona since the terminal is outdoors (but still a “secured” area).

flight was delayed 4+ hours. there was really no understanding of why? weather? the last hour of delay was post boarding. pilot seat was broken. was that the real reason? nonetheless, long day of inconveniences.

Love me some Delta. One of the few airlines to recognize and support veterans. Easy boarding, flight was on time and arrived early and the flight attendants were excellent on this flight.

I thought the service was very nice and pleasant. There were no hiccups and no issues so overall a good experience.

Very good flight. Crew was great. No issues and we even arrived early.

The flights are constantly late anymore, and they won't even give you a glass of water on the plane. For years, they were able to do a service on this flight from Atlanta to Knoxville and Knoxville Atlanta now they say it's too short of a flight. You can't even get a quick drink of water.

Flight got canceled 4 times, missed my connecting flight due to delays, have to wait to go home tomorrow

Third flight in two months where the crew was not there. Comfort seating does not guarantee overhead bin space. Passengers with children are allowed on the plane first - if you are flying to and from Orlando, this means half the plane has boarded before you get on. And somehow all the bin space is taken up. 3 out of 5 flights have had issues with equipment or procedure. Some of these instances caused the flight to be delayed because of a "nuisance" light. One time it was a bag that had been brought on board but did not belong to anyone so we had to return to the gate. Last night we were told the "AC" on the plane doesn't work well and we're 10th for take off- because the crew was late - and that it will get cool when we're in the air. Not sure if this is usual, but I didn't think flight crew could jump seat in first class. Movie and TV selection has not been refreshed for several months- flying one to two round trips each month easily exhausts the list of content.

Great experience nice pilot very soft and easy landing and take off

We sat on the runway for over an hour before departure. That was unwelcome.

Very easy ! Use the kiosk and bag drop and right to security within 10 min

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

This planes staff was top tier. Everything went great and had a great flight home.

Destroyed my suitcase. Tired of talking about it. Cancelling my unite mileage plus account.

New plane was lovely. Crew customer service is always lax but expected. Kraft on time and arrived safely.

It was a short flight so I was expecting too much

Had a one hour delay due to mechanical issue. I didn’t think I’d be able to make my connecting flight, but they waited for me and greeted me when I arrived to help things run smooth.

O’hsre taxi and deboarding took 40 minutes. Needed 20 minutes extra time between connecting flights to avoid running through terminal.

Was great in general, try to respect time and excuses when slight changes have been made, appreciated!

Really hard landing... as in slammed into the runway then hit the brakes really hard ...

Westjet never disappoint always terrible small plane ,crowded cheap snack if you can call it snack

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!

I didn’t have any food but my Prosecco hit the spot. We left on time and the crew was friendly.

I thought the coffee was excellent! The wait for the luggage was acceptable.. It left and arrived on time. My son found that his device worked very well and he really enjoyed his flight! The stewardess moved him up to the emergency exit and he very much appreciated that!

I wasn’t able to book or pay for a seat and they forgot to check me in for my third flight so I spent 24 hours in Toronto waiting for another one.

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.

Flight was overbooked and seats assigned to multiple passengers. Delay 1 hour to sort out.

Good but I don’t received my bags yet is been 5days still no update

It was a short flight so, everything went smoothly and we got to where we needed to be safely.

No TV on the flight. The charging outlet was not working. No food, even a sandwich. The served orange was poor quality.

Selected seats 5 months prior to date. Had email confirmation and seats were not honoured. Family did not sit together

They did not let us board because one member needed a transit visa, which was not evident at the time of ticket purchase.

I was charge a baggage checking fee $68!! I volunteered to check my duffle bag which usually goes under my seat!

I did not like anything because the flight was cancelled yesterday and I did not get to arrive on time in Toronto as I was rebooked with another airline. This caused me to be really stressed out as I am an individual with back injury and to be forced to stay longer in an airport to accommodate a change of airline and the transfers associated with it Due to this I am probably not going to book through your website to eliminate this potentially chaos in the future

shittiest airline in the hemisphere. To improve - start thinking you're flying people, not cattle

Easy boarding, inflight refreshments came on time and comfortable seat

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.