$106 Find Cheap Flights from Seattle 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 Seattle to Ontario departing on 5/16. 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 Seattle 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 Seattle to Ontario, as well as popular online travel agencies
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Flight Deals

Cheap Flights from Seattle to Ontario

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Toronto
Toronto2 stops$228
Ottawa
Ottawa1 stop$383
Thunder Bay
Thunder Bay2 stops$480
London
London1 stop$497
Timmins
Timmins1 stop$585
Toronto
Toronto2 stops$228
Ottawa
Ottawa1 stop$383
Thunder Bay
Thunder Bay2 stops$480
London
London1 stop$497
Timmins
Timmins1 stop$585

Book Cheap Seattle 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 Seattle 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 Seattle to Ontario

Sat, Apr 25 - Fri, May 1
Air Canada Logo
10:20 am - 11:46 pm
SEA
-
YYZ
10h 26m
2 stops
Air Canada Logo
12:30 am - 10:05 am
YYZ
-
SEA
12h 35m
2 stops
$228Air Canada
Sat, Apr 25 - Fri, May 1
Air Canada Logo
8:00 am - 3:54 pm
SEA
-
YYZ
4h 54mnonstop
Air Canada Logo
12:30 am - 10:05 am
YYZ
-
SEA
12h 35m
2 stops
$230Air Canada
Sat, Apr 25 - Fri, May 1
Air Canada Logo
10:20 am - 11:46 pm
SEA
-
YYZ
10h 26m
2 stops
Air Canada Logo
12:30 am - 10:05 am
YYZ
-
SEA
12h 35m
2 stops
$233Air Canada
Sat, Apr 25 - Fri, May 1
Air Canada Logo
10:20 am - 11:46 pm
SEA
-
YYZ
10h 26m
2 stops
Air Canada Logo
12:30 am - 10:05 am
YYZ
-
SEA
12h 35m
2 stops
$235Air Canada
Sat, Apr 25 - Fri, May 1
Air Canada Logo
8:00 am - 3:54 pm
SEA
-
YYZ
4h 54mnonstop
Air Canada Logo
12:30 am - 10:05 am
YYZ
-
SEA
12h 35m
2 stops
$236Air Canada
Sat, Apr 25 - Sat, May 2
Multiple Airlines Logo
8:00 am - 3:54 pm
SEA
-
YYZ
4h 54mnonstop
Multiple Airlines Logo
4:55 pm - 7:23 pm
YYZ
-
SEA
5h 28mnonstop
$244Multiple Airlines
Sat, Apr 25 - Sat, May 2
Alaska Airlines Logo
7:55 am - 3:45 pm
SEA
-
YYZ
4h 50mnonstop
Alaska Airlines Logo
4:55 pm - 7:23 pm
YYZ
-
SEA
5h 28mnonstop
$250Alaska Airlines
Sat, Apr 18 - Sat, Apr 25
WestJet Logo
3:20 pm - 3:13 pm
SEA
-
YUL
20h 53m
1 stop
WestJet Logo
7:30 am - 2:31 pm
YUL
-
SEA
10h 01m
1 stop
$358WestJet
Fri, Apr 17 - Tue, Apr 21
WestJet Logo
3:10 pm - 5:29 am
SEA
-
YKF
11h 19m
1 stop
WestJet Logo
6:20 am - 2:19 pm
YKF
-
SEA
10h 59m
1 stop
$361WestJet
Wed, Apr 15 - Tue, Apr 21
Multiple Airlines Logo
8:41 am - 2:44 pm
SEA
-
YOW
27h 03m
1 stop
Multiple Airlines Logo
5:40 am - 2:19 pm
YOW
-
SEA
11h 39m
2 stops
$404Multiple Airlines
Booking Insights

KAYAK's insights & trends for Seattle to Ontario flights

Get data-powered insights and trends into flights from Seattle 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 Seattle 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 Seattle to Region of Ontario departing in April.

What is the cheapest Seattle to Ontario flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to Ontario from Seattle found in the last 72 hours was to Toronto, at $264 round-trip. The most popular route is from Seattle (SEA) to Toronto Pearson Intl Airport (YYZ), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $264.

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

The average price for all round-trip flights from Seattle 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 morning, when round-trip flights cost $604 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 $604.

Can I save money by flying with a layover from Seattle 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 $407, prices are generally cheapest when you fly direct.

What is the cheapest month to fly from Seattle to Ontario?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle 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 Seattle to Ontario is January, when tickets cost $250 (return) on average. On the other hand, the most expensive months are June and August, when the average cost of round-trip tickets is $483 and $450 respectively.

What’s the cheapest day of the week to fly from Seattle to Ontario?

The average price of all round-trip flights from Seattle to Ontario clicked on KAYAK for each day over the last 12 months.

For Seattle to Ontario, Tuesday is the cheapest day to fly on average and Sunday is the most expensive. Flying from Ontario back to Seattle, the best deals are generally found on Thursday, with Sunday being the most expensive.

How far in advance should I book a flight from Seattle 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 Seattle 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 Seattle to Ontario, you should book around 3 weeks before departure, which saves you about 51% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$106
Best time to beat the crowds with an average 20% drop in price.
Most popular time to fly and prices are also 1% lower on average.
Flight from Seattle to Toronto Pearson Airport

FAQs - booking Ontario flights

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

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Seattle 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 Seattle 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 Seattle 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 Seattle 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 Seattle 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 5 airlines serving from Seattle to Ontario

 
See real verified KAYAK customer reviews for airlines flying from Seattle 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 Seattle 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
Alaska AirlinesOverall score based on 12117 reviews
8.1Boarding
8.5Crew
7.8Comfort
7.0Food
7.0Entertainment
Airline reviews

The final trip home wasn’t as bad as the trip there. Even with the paid upgrade the comfort level was mediocre at best.

6.0 GoodAnonymous, Mar 2026
SEA - JFK
Read more Alaska Airlines reviews

The final trip home wasn’t as bad as the trip there. Even with the paid upgrade the comfort level was mediocre at best.

I paid $129 to be upgraded to better seat only ti be completely ignored by flight attendants I think because I used the front restroom ???? I was dozing off and on but I was never once offered a beverage or snack but my seat mates were served numerous double vodkas. I want my money back. I tried to call Alaska Airlines complaints phone number and was told it was 2.5 hours to hold.

Don’t fly with Alaska if you have a layover in Seattle. Guaranteed to screw you over. We waited at terminal S3 &were >2 hours delayed(mechanical issues)and told to change terminals to a different plane that required riding 3 shuttles to get to new terminal N14. Then they delayed the flight even further and changed gates again. when I went to the customer service in terminal N, the manager turned me away without apologizing & refused to assist me but mandated I leave her alone as her shift is nearly finished and insisted I totake another 2 shuttles to terminal C so I can just talk to another service rep while dragging my family of 4/ kids in tow.

i canceled my flight from SEA to SFO, SNA to SEA and received full refund from Alaska Airlines. i am pleased with the customer service.

Departing flight for our weekend trip was cancelled due to weather which meant our return flight was useless. The whole thing was difficult to get support through but Alaska did recover and was able to reimburse us for the flights yesterday. For some reason, Kayak was not kept in the loop, adding to the confusion.

i canceled my return flight package with Alaska Airlines. Customer Service was excellent and assisted me to cancelled both of our reservations and returned the payment in full. that is excellent service and understanding and empathy of the customers' needs. i like Alaska Airlines and recommend AS to everyone.

Never got on because the airline sent the WRONG plane to take us on our first leg of the trip so we missed ALL connecting flights. No help available from anyone at the airline…

The crew inside the airport for Alaska was rude, lazy and incompetent

The flight was extremely smooth, and so was the landing. Great piloting.

Plane was clean, staff was professional and flight was on time. No built in tv was still ok, as programs were offered that could synch to smart phones.

I took seat 15A in anticipation of window seat, there is no window.

The first class flight attendant was awful to everyone. Very rude; no customer service. She should not be working in first class.

Snacks and included beverages were appreciated. Boarding went smoothly. Plenty of overhead bin space. Seats get very uncomfortable after a couple of hours. After waiting 10 painful minutes for my walker, a very nice Delta guest agent pushed me in a wheelchair to the gate. It was finally delivered to me after another 15 minutes . Our checked bag was on the carousel long b4 I was able to retrieve it. Fortunately it was still there but somewhere along the way the straps we used to secure it were removed and and were not reattached. Wish I had made note of the agents name.

It was fine. 55 minute flight. No snacks or beverage service offered. Boarding went smoothly and my walker was waiting for me on the jet way.

Smaller plane for a longer flight than my first one. Doesn’t make sense.

The cabin temperature was nice and cool. The wifi was not working.

Could not get my connecting flight boarding pass until four hrs before departure! Ver annoying especially since the staff could not explain why!

First flight out and was 85 minutes delayed. Notification came out way too late

Was forced to check in my small carry on, even though I informed the crew it has very fragile items inside

First class and monitors weren’t working for mine & my husbands. Eventually fixed, but quite annoyed as we bought first class. Also, No foot rests.

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

Entertainment kept turning itself off. Gave up on watching a movie.

Wifi took a while to kick in and we had a maintenance issue that took over 40 mins at the gate in Washington before pulling back

Not United Airlines' fault. It's ORL airport's fault.

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.

Very nice flight love the small aircraft. We had a wonderful flight attendant. Nice to see someone that really enjoys her job. Don't have her name but had a southern accent.

Seats in waiting area and on plane hard as rock. Fast internet on the flight was great! Crew was kind.

United needs to step up their game. Delayed flight leaving Seattle, San Francisco. Older aircraft, not very comfortable.

Not the fault of United—weather, reroute around weather, time sitting on tarmac, arrived couple hours late, too late for train into city necessitating a much pricier cab but weather…can’t be helped.

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

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.

I didn't think about not having the right app for wifi because my connecting flight was with Westjet and when I took off from Seattle I was thinking I would use my wifi, but realized I couldn't on my Westjet app and I did not have Delta's app downloaded.

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

I want to thank Carlos at the Miami AC desk - he was amazing and went over and above to help us out. Thank you Carlos and all the best to you!!! You made our faith in AC feel great! Sincerely, David Cubitt

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.

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 Seattle to Ontario

Information on your arrival and departure airports