$121 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 9/3. 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
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 24% 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$273
Ottawa
Ottawa1 stop$355
Thunder Bay
Thunder Bay1 stop$329
London
London1 stop$314
Timmins
Timmins1 stop$601
Toronto
Toronto1 stop$273
Ottawa
Ottawa1 stop$355
Thunder Bay
Thunder Bay1 stop$329
London
London1 stop$314
Timmins
Timmins1 stop$601

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, Jun 24 - Mon, Jun 29
WestJet Logo
10:30 am - 10:45 pm
SEA
-
YYZ
9h 15m
1 stop
WestJet Logo
12:00 pm - 6:45 pm
YYZ
-
SEA
9h 45m
2 stops
$273WestJet
Tue, Jun 9 - Tue, Jun 16
WestJet Logo
10:30 am - 11:59 pm
SEA
-
YYZ
10h 29m
2 stops
WestJet Logo
3:50 pm - 9:00 pm
YYZ
-
SEA
8h 10m
1 stop
$275WestJet
Sat, Aug 1 - Sun, Aug 9
WestJet Logo
10:30 am - 9:15 pm
SEA
-
YYZ
7h 45m
1 stop
WestJet Logo
6:10 am - 6:45 pm
YYZ
-
SEA
15h 35m
2 stops
$276WestJet
Thu, Jun 4 - Tue, Jun 16
WestJet Logo
7:35 pm - 5:45 am
SEA
-
YYZ
7h 10m
1 stop
WestJet Logo
3:50 pm - 9:00 pm
YYZ
-
SEA
8h 10m
1 stop
$277WestJet
Sat, Jun 6 - Fri, Jun 12
Air Canada Logo
5:45 am - 6:22 pm
SEA
-
YTZ
9h 37m
2 stops
Air Canada Logo
8:55 pm - 10:05 am
YTZ
-
SEA
16h 10m
2 stops
$339Air Canada
Sat, Jun 6 - Fri, Jun 12
Air Canada Logo
7:20 pm - 10:57 am
SEA
-
YTZ
12h 37m
2 stops
Air Canada Logo
12:15 pm - 7:05 pm
YTZ
-
SEA
9h 50m
1 stop
$361Air Canada
Fri, Jun 19 - Mon, Jun 29
Multiple Airlines Logo
7:00 am - 5:15 pm
SEA
-
YHM
7h 15m
1 stop
Multiple Airlines Logo
6:15 am - 6:45 pm
YHM
-
SEA
15h 30m
3 stops
$421Multiple Airlines
Mon, Jun 8 - Mon, Jun 15
Multiple Airlines Logo
10:30 am - 5:15 pm
SEA
-
YHM
27h 45m
1 stop
Multiple Airlines Logo
8:50 am - 9:00 pm
YHM
-
SEA
15h 10m
2 stops
$424Multiple Airlines
Fri, Jun 5 - Tue, Jun 9
United Airlines Logo
10:40 pm - 10:06 am
SEA
-
YTZ
8h 26m
1 stop
United Airlines Logo
12:15 pm - 7:05 pm
YTZ
-
SEA
9h 50m
1 stop
$477United Airlines
Sat, Jun 6 - Tue, Jun 9
United Airlines Logo
7:05 pm - 10:06 am
SEA
-
YTZ
12h 01m
2 stops
United Airlines Logo
12:15 pm - 7:05 pm
YTZ
-
SEA
9h 50m
1 stop
$483United 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 June.

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 $353 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 $353.

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 $606 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 $606.

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 $505, 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 $88 (return) on average. On the other hand, the most expensive months are June and February, when the average cost of round-trip tickets is $165 and $149 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 Tuesday 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 53% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 10 weeks before departure.

Good to know

Low seasonMarch
Cheapest flight$121
Best time to beat the crowds with an average 31% drop in price.
Most popular time to fly with an average 1% increase in price.
Flight from Seattle to Montreal

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 12354 reviews
7.8Comfort
7.0Food
7.0Entertainment
8.1Boarding
8.5Crew
Airline reviews

I had to cancel this trip due to medical reasons. I took out flight insurance but I was unable to cancel my reservation on either Kayak or Alaska. I need proof that I did not take this flight to get my refund. I have tried for a week and a half together that information from either Kayak or Alaska but so far I have gotten no response. I am very disappointed!

2.0 MediocreDave, May 2026
SEA - PSP
Read more Alaska Airlines reviews

I had to cancel this trip due to medical reasons. I took out flight insurance but I was unable to cancel my reservation on either Kayak or Alaska. I need proof that I did not take this flight to get my refund. I have tried for a week and a half together that information from either Kayak or Alaska but so far I have gotten no response. I am very disappointed!

We had paid for window seats just to not get window seats. When we ask the flight attendant to switch seats she said no because it was a full flight. It was the the worst experience I had ever.

The crew seem untrained and uncertain no one ever checked up on us in our first class cabin. I had to ask for water four times and the lady kept saying she was busy when they weren't really doing anything. Had to walk to the back of the plane to get water for myself. Crew seem new and unexperience. You can tell this by the fumbling they kept making trying to fight. (I miss Hawaiian air.)

Alaska airlines agent helped me greatly to reschedule my flight. The flight was also very comfortable and the flight attendants were very friendly.

The crew was great and everything went smoothly coming and going.

My window seat did not have a window. I chose seat 11A thinking I would have a view. I had a wall instead.

See what I wrote in the previous section. This was a terrible experience. I would like refund.. I even paid an extra $70 for an aisle seat closer to the front to ensure that I got off early enough to catch the next flight. The fact that the plane did not wait, and even left eearlier, knowing that the first flight came in late, and was moved to a terminal three train stops away is appalling. My friend that flew JetBlue, their flight was delayed and came in later and the connecting flight WAITED for them. How is it that JetBlue could do that, and Alaska could not.

This was my second time flying Alaska Airline in the 1st Class cabin. Everything was fine with the exception of the food and entertainment. The food was just ok but not what I was expecting from 1st Class. A BBQ pork sandwich and baked potato. There wasnt any in-flight entertainment. I found that odd since it was a coast to coast flight Seattle to Dulles. My sister flew 1st Class on Delta on a shorter flight ( Seattle to Cincinnati) and had an awesome meal and in-flight entertainment. I typically fly Delta but there wasn’t a flight with times that fit my schedule. I am by no means a primary donna. But when my upgrade cost over $900…I didn’t use any reward miles…I was expecting more than what I got. I will never fly Alaska Airline 1st Class again. I will stick with Delta for all my travel needs whether it’s in 1st Class or coach.

Good staff. Comfortable seats. Had to check my bag because the flight was too full.

Loved this first class flight! Awesome food, snacks and drinks. Comfortable seat with foot rest. Good movie. Very friendly crew! Only thing I would suggest is having a screen on seat back in front of me so I didn’t have to watch the movie on my phone.

Bus to plane was delayed for no apparent reason and our luggage was still on the belt when they shut it off. Took about 20 minutes to turn it back on to get our luggage.

It was a pleasant surprise to have complimentary Wi-Fi on the flight

Much better than Latam, the worse airline company ever. I hope I don't have the need to fly Latam ever in my life again.

Crew was nice, meal was good. Entertainment had to be rebooted 3 times and still did not work. Turns out there was residue on screen, it needed to be cleaned to prevent the touchscreen buttons from continuously activating. I had entertainment for the last 45 minutes of a 5 hour 45 minute flight. Really unacceptable for first class. Flight attendent indicated your cleaning solution creates this problem. Seems as if this is widely known, you should be using a different product or cleaning better. Really really disappointing which simply added to the wi fi on your planes with reliably never ever works.

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.

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

Some crew were unfriendly or in some cases just straight up rude.

Putting people that close to the bathroom, where you have to look into the bathroom as people are exiting and entering was not great and the smell was also not great. I know the airlines are desperate for more chairs, but that seat is a crime.

one staffer was frustrated (it happen); the flight was late and the pilot mentioned they'll make amend but the snacks were the same, other than that the aircraft was clean and everything went smooth, no complaints

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.

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.

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

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

It was good that our flight left early. It was a nice smooth flight and landing.

All good……but luggage didn’t make it on the airplane. Had to wait 3 days. Was a bummer.

Small suitcase used for carryon the last time was refused by boarding crew this time. Appears to be at the discretion and mood of the person on the day. Flight was only half booked, there would have been no problem with space.

It was a problem because there was a delay where we sat before taking off from newark,then when landed in Toronto we sat on tarmac and they wouldn't let us out for a long period of time. When we finally were released to the airport in Toronto the attendant scanned our boarding pass that we were here for our connection to Brazil. We ran all the way to the gate and they said at the gate the door is shut so we can not let you on the plane. We explained that we were checked in by the attendant when we arrived at Toronto airport to go to Brazil and they should not have shut the door. We were ignored at the gate

Flight home was delayed multiple times, did not get home until 2am

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

Information on your arrival and departure airports