$108 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 10/20. 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

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
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 22% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Seattle to Ontario

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Toronto
Toronto1 stop$238
Ottawa
Ottawa1 stop$253
London
London1 stop$565
Toronto
Toronto1 stop$238
Ottawa
Ottawa1 stop$253
London
London1 stop$565

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

Tue, Oct 21 - Fri, Oct 24
Multiple Airlines Logo
12:17 am - 10:59 amSEA-YYZ
7h 42m1 stop
Multiple Airlines Logo
12:00 pm - 7:21 pmYYZ-SEA
10h 21m2 stops
$238Multiple Airlines
Find Deal
Sat, Oct 25 - Wed, Oct 29
WestJet Logo
8:40 am - 12:31 amSEA-YYZ
12h 51m2 stops
WestJet Logo
7:45 am - 2:20 pmYYZ-SEA
9h 35m1 stop
$239WestJet
Find Deal
Mon, Mar 23 - Sat, Mar 28
WestJet Logo
3:10 pm - 5:29 amSEA-YKF
11h 19m1 stop
WestJet Logo
7:00 pm - 2:19 pmYKF-SEA
22h 19m1 stop
$239WestJet
Find Deal
Sat, Oct 25 - Wed, Oct 29
Alaska Airlines Logo
7:18 am - 3:00 pmSEA-YYZ
4h 42mnonstop
Alaska Airlines Logo
4:45 pm - 7:05 pmYYZ-SEA
5h 20mnonstop
$240Alaska Airlines
Find Deal
Fri, Oct 24 - Tue, Oct 28
Multiple Airlines Logo
1:50 pm - 12:22 amSEA-YYZ
7h 32m1 stop
Multiple Airlines Logo
4:45 pm - 7:05 pmYYZ-SEA
5h 20mnonstop
$241Multiple Airlines
Find Deal
Mon, Nov 3 - Sun, Nov 16
Alaska Airlines Logo
7:55 am - 3:35 pmSEA-YYZ
4h 40mnonstop
Alaska Airlines Logo
4:45 pm - 7:05 pmYYZ-SEA
5h 20mnonstop
$247Alaska Airlines
Find Deal
Tue, Mar 10 - Wed, Mar 11
Air Canada Logo
8:00 pm - 6:43 amSEA-YOW
7h 43m1 stop
Air Canada Logo
9:15 am - 10:16 pmYOW-SEA
16h 01m1 stop
$253Air Canada
Find Deal
Tue, Nov 4 - Wed, Nov 12
Air Canada Logo
10:05 am - 9:29 pmSEA-YYZ
8h 24m1 stop
Air Canada Logo
7:50 pm - 10:16 pmYYZ-SEA
5h 26mnonstop
$257Air Canada
Find Deal
Fri, Oct 17 - Sat, Oct 18
United Airlines Logo
11:10 pm - 2:30 pmSEA-YYZ
12h 20m1 stop
United Airlines Logo
5:15 pm - 10:30 pmYYZ-SEA
8h 15m1 stop
$263United Airlines
Find Deal
Tue, Mar 10 - Wed, Mar 11
United Airlines Logo
6:31 am - 9:14 pmSEA-YOW
11h 43m1 stop
United Airlines Logo
3:11 pm - 9:50 pmYOW-SEA
9h 39m1 stop
$266United Airlines
Find Deal
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.

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 $261 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 $261.

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 $382, 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 $282 (return) on average. On the other hand, the most expensive months are June and July, when the average cost of round-trip tickets is $497 and $466 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 Saturday 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 4 weeks before departure, which saves you about 58% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$108
Best time to beat the crowds with an average 11% drop in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from Seattle to Hamilton

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.

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

    The cheapest time of day to fly to Ontario is generally in the evening, when round-trip flights cost $283 on average. Morning departures are around 118% more expensive than evening flights, on average. The most expensive time of day to fly to Ontario is generally at night, which is peak travel time and where the average cost of a ticket is $774.

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.
8.0
Alaska AirlinesOverall score based on 10000 reviews
7.0Entertainment
8.1Boarding
8.5Crew
7.1Food
7.8Comfort
Airline reviews

Plane seats are comfortable and seemed more roomy than others I have been on. Playing was clean and flight crew friendly. Passengers who have a connecting flight should however be allowed off the plane first

10.0 ExcellentJILL, Sep 2025SEA - SBP
Read more Alaska Airlines reviews

Plane seats are comfortable and seemed more roomy than others I have been on. Playing was clean and flight crew friendly. Passengers who have a connecting flight should however be allowed off the plane first

flights on time, flights that were leaving when scheduled..having the alaska people on the phone and most of all getting rid of the new atmos website it is terrible!!!!!!!!

6 hour flight, just crackers and drinks. No WiFi, no tv, and tight seats. Just like every other airline.

Seattle airport terminal was a nightmare to navigate. Coming g off a cruise boat etc. Lack of convient Restrooms a major issue. Once able to get to boarding Alaska Air it was good experience.

I don’t want to pay extra to choose my seat

SeaTac airport hottible No signage to tell you where to go Took one and half hour to make to gate after being dropped at airport HORRIBLE LOTS OF yelling at patrons EXTREMELY HORRIBLE AND SCARY!

Appreciated the upgrade on the saver ticket. Made the 5 hour flight bearable.

Only issue was at the gate the clerk tried to get us to check our carry on bags. When I questioned the other clerk said, the flight isn't full, they are fine to carry on

The best thing were the seats It was too cold most of the time. The food was poor… The eggs were runny and potatoes were cold. The last time I flew first class we had a TV screen to watch movies but not this time The last time we had free alcohol, but not this time

All flights were on time. No crowded and had empty seats. All flight attendents were great.

Cramped seating for me. Luckily it wasn’t a long flight

Lounge in Lagos is terrible, food on board from Lagos to Atlanta was horrible. Only bright spot the cabin crew were awesome.

The airport was reasonably clean. The boarding process reasonably efficient. The cabin crew was efficient, polite but not that friendly. The food quality was unremarkable and the choices were awful . There was either a so so chicken dish or a “ vegetarian “ option which was really cheap carbohydrates drowned in cheese. Signing onto i flight wifi was not straightforward. Overall it was a very average experience

The staff and the boarding procedure were all amazing . The one flight was not equipped with WIFI which now adays seems odd. All in all the experience was good

Passengers need to check in big baggage instead of bringing on the plane. That cause inconvenience for everyone. Otherwise flight was good.

Perfect flight both ways. On time, courteous staff, plane comfortable and cool. Best domestic flights I’ve had in awhile.

The food was terrible especially for a 15 hour international flight. The crew was unpleasant as well.

Really low quality food especially for an international flight. The crew also was surprisingly unpleasant except couple of ladies. I know we were not in first class but that’s no reason to treat customers as less.

Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.

Quick check in. Everything went smooth. I don't know what can be done about airline food.

I had no checked baggage but was required to hand over carry on baggage at the door of the plane. There was a lot of overboard space in the plane and I was one of the last ones. I ran to get my carry on but it was gone. I was given back at the plane door in Toronto, so the wait was not as long as it would have been at the carousel.

We had a layover from YVR to Denver. We bought 4 bottles of Absolut Vodka at the YVR Duty Free for $116.20, after going through security and American Customs Pre Clearance at YVR, Vancouver. When we landed in Denver, United put us behind the American Customs as well as TSA again for some reason. We were forced to go through American Customs and TSA again. TSA confiscated our rightfully owned Duty Free Absolut Vodka bottles. Because United incorrectly forced our flight behind American border and TSA again, we missed the connecting flight. After United put us on a later flight, we eventually arrived in Chicago very late, with hardly any sleep. I am looking for compensation from United for our incorrectly confiscated Absolut Vodka bottles worth $116.20, as well as compensation for incorrectly putting us behind American Customs and TSA again, causing us to miss our connecting flight, making us arrive extremely late in Chicago.

From the first moment you interact with United Airlines, you can expect nothing less but extreme frustration. The baggage handler at the bag drop seems completely unbothered by the presence of customers waiting in line. No help was extended to load the baggage whatsoever. And if any of your bags is overweight by 0.01 pound they will make you re-distribute everything in your suitcase just to play power trip. When it was time to board no help was extended to customers to locate their seats. Moreover. It was a chaotic mess at the gate when it was unclear who should board first and everyone just bunched up, trying to get on the plane. I am sure the crew was doing their best to perform their jobs while being paid their wages however it shouldn’t be that hard to smile once or twice when you’re in the business if serving customers. It is a shame for the United States of America to have a flagship carrier of such low caliber. Our flight was also delayed by about an hour and a half due to further delays prior to our inbound flight. Being someone who has travelled for both business and leisure in Asia, Europe, and South America I have never experienced such poor quality of service.

Had to cancel first flight because Airporter Bus took over 3 hrs to get to airport which resulted in an extra $378 dollar fare . Is there anyway I can be reimbursed for initial fare since it was not my fault? Sent from my iPhone EJ Ledet

The pilots were late and it made us 1 hour late. The meat was tough and bok choy was also tough.

the delay for 3 hours was understandable due to weather conditions but the flight should’ve provided some on flight compensations or at least provide more food.

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.

Boarding experience was smooth. Flight attendants were friendly and helpful. Entertainment system on the Houston-Edmonton flight did not function for passengers on the left side of the aisle. On the bird's eye flight from Quito to Houston, they should not serve a meal. No one needs to eat after midnight and it is disturbing for those passengers trying to sleep.

Flight was late as pilot crew had to land at different airport in their previous flight. Passengers boarded and had to wait for pilots inside plane. Series of incomplete and unnecessary announcements by an annoying voice, rather than complete, informative announcements.

Delay and keep changing gates. I have to run around from B to C then to E.

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

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!

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.

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

Didn’t realize I purchased a basic fare with no carry ons allowed. Not very well communicated. Also had seats switched without knowledge and had to pay for different ones.

We loved our Air Canada experience and will definitely fly them again. It just so happened than in the first leg of our trip their entertainment system was not working, and neither was their oven so cold meal & snacks only.

Short flight. Everything was fine except the flight was delayed twice for a total of an hour.

I found the boarding easy and my seat was very comfortable as I had a lot of leg room. I am not too happy that I no longer have lounge access even though I used to get it with my TD credit card.

Flight cancelled. Major disruption to our travel. Do not use Air Canada from KC. To few flights.

There labor disputes cancelled my flight less than 24 hours before my boarding time but there customer service/website was easy enough to navigate and they rebooked me for no upcharge.

Re luggage I carried a backpack only. I did not check any bags in. However there were other passengers with carry on luggage going in the plane. My question is why are others allowed to have a carry on luggage inside the plane? Shouldn’t they have dropped it off at the gate? I’m asking because I could have brought the same thing instead of a backpack only. Please clarify for future reference. Thank you.

Like the service. Very hard to communicate or contact when have problems

Check in staff was incredibly rude and condescending. When I arrived at the gate I had been charged $125 for a checked back. I did have or check a bag. When I brought this to the attention of the staff member who checked me in, she said that she made a mistake and there was nothing she could do about it. I asked her to remove the charge and refund credit card, she said she could not and that I had to call my credit card company to contest the charge. I called Air Canada customer support, was put on hold, after 43 minutes a received a messages stating customer service was overwhelmed with calls and was then hung up on.

Refreshments and Air Hostess was good. Issues with customs in Toronto caused flight to depart and left me behind twice. Vouchers for delayed flight needs to increase.

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

Information on your arrival and departure airports

Not what you’re looking for? Find thousands of other hotels, flights, car rentals and package deals with KAYAK.