$100 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 5/4. 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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Cheap Flights from Seattle to Ontario

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Toronto
Hamilton1 stop$225
Ottawa
Ottawa1 stop$235
Thunder Bay
Thunder Bay1 stop$296
London
London2 stops$273
Timmins
Timmins2 stops$570
Toronto
Hamilton1 stop$225
Ottawa
Ottawa1 stop$235
Thunder Bay
Thunder Bay1 stop$296
London
London2 stops$273
Timmins
Timmins2 stops$570

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

Wed, Feb 4 - Sun, Feb 8
WestJet Logo
3:10 pm - 5:16 pm
SEA
-
YHM
23h 06m1 stop
WestJet Logo
6:10 pm - 2:19 pm
YHM
-
SEA
23h 09m1 stop
$225WestJet
Wed, May 20 - Sun, May 24
WestJet Logo
7:05 am - 6:25 pm
SEA
-
YOW
8h 20m1 stop
WestJet Logo
7:45 am - 1:08 pm
YOW
-
SEA
8h 23m1 stop
$235WestJet
Tue, Apr 28 - Wed, May 6
WestJet Logo
2:05 pm - 12:42 am
SEA
-
YUL
7h 37m1 stop
WestJet Logo
6:45 am - 1:08 pm
YUL
-
SEA
9h 23m1 stop
$240WestJet
Fri, Jan 16 - Tue, Jan 20
United Airlines Logo
12:57 pm - 2:01 pm
SEA
-
YYZ
22h 04m2 stops
United Airlines Logo
3:45 pm - 10:59 pm
YYZ
-
SEA
10h 14m1 stop
$246United Airlines
Sat, Jan 24 - Sat, Jan 31
United Airlines Logo
8:10 am - 11:46 pm
SEA
-
YYZ
12h 36m1 stop
United Airlines Logo
4:10 pm - 9:15 pm
YYZ
-
SEA
8h 05m1 stop
$248United Airlines
Thu, Jan 15 - Fri, Jan 16
Air Canada Logo
9:55 am - 10:41 pm
SEA
-
YYZ
9h 46m2 stops
Air Canada Logo
7:00 am - 2:31 pm
YYZ
-
SEA
10h 31m1 stop
$250Air Canada
Thu, Jan 15 - Mon, Jan 19
Air Canada Logo
8:10 am - 3:53 pm
SEA
-
YYZ
4h 43mnonstop
Air Canada Logo
10:00 am - 10:06 pm
YYZ
-
SEA
15h 06m2 stops
$252Air Canada
Sat, Jan 10 - Sun, Jan 18
Alaska Airlines Logo
7:55 am - 3:35 pm
SEA
-
YYZ
4h 40mnonstop
Alaska Airlines Logo
4:45 pm - 7:17 pm
YYZ
-
SEA
5h 32mnonstop
$254Alaska Airlines
Sat, Jan 10 - Mon, Jan 19
Multiple Airlines Logo
7:55 am - 3:35 pm
SEA
-
YYZ
4h 40mnonstop
Multiple Airlines Logo
9:45 am - 8:39 pm
YYZ
-
SEA
13h 54m1 stop
$256Multiple Airlines
Mon, Apr 13 - Sun, Apr 26
Multiple Airlines Logo
11:55 am - 2:44 pm
SEA
-
YOW
23h 49m2 stops
Multiple Airlines Logo
3:45 pm - 8:28 pm
YOW
-
SEA
7h 43m1 stop
$302Multiple 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.

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 $225 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 $225.

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 $342, 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 November, when tickets cost $274 (return) on average. On the other hand, the most expensive months are December and June, when the average cost of round-trip tickets is $553 and $497 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 Wednesday, 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 62% 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$101
Best time to beat the crowds with an average 21% drop in price.
Most popular time to fly and prices are also 3% 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.

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

    The cheapest time of day to fly to Ontario is generally in the morning, when round-trip flights cost $607 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 $607.

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 11562 reviews
8.1Boarding
8.5Crew
7.1Food
7.0Entertainment
7.8Comfort
Airline reviews

The ticket I purchased through Kayak did not show up in my Alaska Airlines app, and neither of the codes given to me worked for online check in. I've never had to show up to the airport at 6am wondering if I've been scammed. Cheap flight fare or whatever does not play well with airlines and I will be wary of using Kayak in the future.

2.0 MediocreMorgan, Dec 2025
SEA - OAK
Read more Alaska Airlines reviews

The ticket I purchased through Kayak did not show up in my Alaska Airlines app, and neither of the codes given to me worked for online check in. I've never had to show up to the airport at 6am wondering if I've been scammed. Cheap flight fare or whatever does not play well with airlines and I will be wary of using Kayak in the future.

Crew was rude and passive aggressive when i told them I didnt want to check my duffel bag. Then a crew member slammed my bag to the side when organizing the overhead compartment. The plane had worn leather seats with no infotainment. Plane landing was noticeably rough (this is the one year ive flown multiple times and out of american and delta this was the worst). The only redeeming quality is that we were noticeably earlier than we should have been.

The plane was delayed which was annoying. No seat back screens is a bummer. Staff if great

I got my seat changed last minute so a parent coumd sit with their child wich i found out was a teenager

I wish you would have just canceled the Saturday flight from sea to rdd on Dec 13. the diversion cost me more time and money than if I had just rebooked to Sacramento. It was a huge headache and cost.

There was no food or entertainment so quit asking about that! Everything else was fine.

I wasn’t assigned a seat until last minute even though I checked in 24 hours before the flight and was told I might not be able to get on the flight! The leg room and seat room in the flight was abysmal. The service both at boarding and on the flight was very mediocre and not particularly friendly.

Late boarding, older plane. Great flight, no issues. Very cold inside the plane.

The plane was old so the seats were very worn out. The seats were hard, uncomfortable, and caused me actual pain. The lights were too bright. The flight itself was fine.

1. Denial of Basic Needs (SEA): Upon arrival in Seattle, the wheelchair attendant refused my urgent request to use the restroom, insisting on scanning documents first. She eventually took me to a restroom but then abandoned me and my autistic son at an unstaffed, deserted gate for over four hours. When I called the accommodation line for help, I was told to "get someone's attention," which was impossible. My son, traumatized by the prospect of me yelling for help, was forced to wander the terminal to find assistance. 2. Revocation of Accommodations & Threats: At the gate, an agent stated I had no accommodations on file, despite my previous leg having them. When I showed the app (where my bulkhead seat was erased and replaced with Row 14), he denied the evidence. When I attempted to advocate for my immobilized leg, he threatened to "yank me from the flight" if I said one more word. He coerced me into agreeing that I was "asking for accommodations for the first time" before he would allow assistance, effectively forcing me to falsify the situation under duress. I complied only out of fear of being stranded in a strange city. 3. On-Board Negligence and Injury: Because my bulkhead seat was revoked, I was forced into Row 14. With my leg immobilized and unable to bend, it extended into the aisle. During boarding and the flight: 16 different passengers tripped over my injured leg. 6 rolled luggage bags were pulled over my injured leg. The Flight Attendant (FA) was one of the people who tripped and drove luggage over me. I reported the issue to the FA after 10 trips and 3 luggage impacts. He ignored me. He only addressed me later to ask me to move my immobilized leg for beverage service. I informed him again: "16 people have tripped, 6 luggage runovers, I cannot bend it." He provided no medical aid and no incident report. 4. Resolution and Trauma: Eventually, a different employee noticed my distress and my original paper boarding pass showing the correct bulkhead assignment. He asked me to move up. I broke down in tears, terrified that moving would cause the gate agent to remove me from the plane as threatened. We were eventually moved to the bulkhead, but the damage was done. My autistic son was traumatized by watching his mother be trampled and threatened. 5. Post-Flight: I called to report these injuries, but was disconnected after a 45-minute hold. I require a formal record of this injury and these violations.

The only thing nice I can say is the flight crew was really nice and apologetic about the situation. They shared as much information as they had and advised us on what we could do about missing connecting flights. The boarding process was so slow. The gate agent was working by herself and should have had someone working with her. It took almost an hour to board because she was trying to board a full flight of people and provide customer service to everyone who was flying standby and/or had questions. It was really chaotic. This didn't help the fact that we were delayed and folks were missing connections the longer it took.

The gate attendants and the crew were terrible. Because of high winds, they needed to carry more fuel, so they had to get volunteers to take the next flight at 6 am the next day. They did a terrible job of it - our flight ended up taking off just under 3 hours of the scheduled time. I hope to never fly Delta again.

Did not realize internet screen was hidden between seats and no info printed!!!!

2 of the seats in row 31 the entertainment system was not working, and one seat the tray table did not go all the way down. Flight arrived early and departed on time which was great.

Very good flight crew and very nice people staff were incredible especially the gate agent

Waited at the usual crowded gate at DCA where one ends up standing up because there aren't enough seats.

The flight was delayed for about 2 hrs. Other than it, it was good.

Advertised fruit trays with cheese, but only snacks handed out!

The plant way delayed departing by 3 hours. It was an old airplane with broken seats and armrests. The bathroom made a hollering sound. A really crappy flight experience and travel day all around.

Flight delays both to Detroits and return flight . The flight to Detroit was associated with mechanical difficulty

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 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.

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

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!

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

I would like to get my money back. I flight was 4 hours late on the way to detroit, And same on my way back to Brussels they cancelled my flight and give me an other ticket and i had to wait 5 hours.

All attendents were very efficient, pleasant and happy. Everything went smoothly. The seats could have been wider. There could have been more free food instead of just one small bar.

My seat was one of those that couldn't recline, but the problem was that it was abnormally upright, so the headrest actually made the seat concave, which was uncomfortable and hard on my lower back. I had to ball my jacket up and use it as lumbar support. goodness I had it with me.

I liked a lot , the flight attendant so nice ,the seat very comfortable I enjoyed the flight , I will do it again with Air Canada,

Elderly female flight attendant was not customer friendly. There were only about 12 people on a regional jet that had about 60 seats. There were 8 exit row seats and none of them were taken. We attempted to sit in those seats and the flight attendant gave the standard " you didn't pay for those" so she would not allow us to move. What harm would that have caused ? They assigned seats to 5 of the 12 people in 2 rows, row 20 and 21. A simple friendly customer experience gesture of allowing us to sit in exit rows would have gone a long way in me having a very favorable impression on Air Canada. After that I have very poor impression of Air Canada and will not fly with them when I can avoid it.

Pearson Airport could not properly handle all the passengers who they needed to process in order to properly get them on board. As a result, I missed the departure of my flight from Toronto. The only saving grace is that Air Canada found a flight that only delayed me by one hour. However, this was no thanks to Pearson Airport!

Almost everything it was a “cool” ambiance but we arrived to Toronto so that it’s ok for me

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

Information on your arrival and departure airports