$163 Find Cheap Flights from Seattle 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 Seattle to Ontario departing on 9/6. 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
Toronto1 stop$338
Ottawa
Ottawa1 stop$442
Thunder Bay
Thunder Bay1 stop$559
London
London1 stop$388
Timmins
Timmins1 stop$626
Toronto
Toronto1 stop$338
Ottawa
Ottawa1 stop$442
Thunder Bay
Thunder Bay1 stop$559
London
London1 stop$388
Timmins
Timmins1 stop$626

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

Fri, Sep 18 - Wed, Sep 23
WestJet Logo
7:35 pm - 5:45 am
SEA
-
YYZ
7h 10m
1 stop
WestJet Logo
12:00 pm - 6:45 pm
YYZ
-
SEA
9h 45m
1 stop
$338WestJet
Tue, Sep 8 - Tue, Sep 15
WestJet Logo
10:30 am - 9:15 pm
SEA
-
YYZ
7h 45m
1 stop
WestJet Logo
1:30 pm - 6:45 pm
YYZ
-
SEA
8h 15m
1 stop
$341WestJet
Wed, Sep 9 - Fri, Sep 18
WestJet Logo
7:35 pm - 5:45 am
SEA
-
YYZ
7h 10m
1 stop
WestJet Logo
1:30 pm - 6:45 pm
YYZ
-
SEA
8h 15m
1 stop
$344WestJet
Thu, Sep 10 - Sun, Sep 13
WestJet Logo
7:35 pm - 5:45 am
SEA
-
YYZ
7h 10m
1 stop
WestJet Logo
12:00 pm - 6:45 pm
YYZ
-
SEA
9h 45m
1 stop
$345WestJet
Wed, Sep 9 - Tue, Sep 29
WestJet Logo
7:35 pm - 5:45 am
SEA
-
YYZ
7h 10m
1 stop
WestJet Logo
1:30 pm - 6:45 pm
YYZ
-
SEA
8h 15m
1 stop
$346WestJet
Tue, Oct 13 - Thu, Oct 15
Multiple Airlines Logo
7:35 pm - 7:05 am
SEA
-
YUL
8h 30m
1 stop
Multiple Airlines Logo
6:00 pm - 10:42 pm
YUL
-
SEA
7h 42m
1 stop
$398Multiple Airlines
Tue, Oct 13 - Thu, Oct 15
Air Canada Logo
3:00 pm - 7:10 am
SEA
-
YUL
13h 10m
2 stops
Air Canada Logo
10:40 am - 9:04 pm
YUL
-
SEA
13h 24m
2 stops
$402Air Canada
Tue, Oct 13 - Thu, Oct 15
Air Canada Logo
3:00 pm - 7:10 am
SEA
-
YUL
13h 10m
2 stops
Air Canada Logo
2:10 pm - 9:04 pm
YUL
-
SEA
9h 54m
1 stop
$404Air Canada
Wed, Jul 15 - Wed, Aug 19
Air Canada Logo
10:45 am - 7:51 am
SEA
-
YTZ
18h 06m
2 stops
Air Canada Logo
12:30 pm - 10:42 pm
YTZ
-
SEA
13h 12m
2 stops
$537Air Canada
Mon, Sep 21 - Wed, Sep 23
Air Canada Logo
10:50 am - 1:15 pm
SEA
-
YTZ
23h 25m
2 stops
Air Canada Logo
6:50 am - 10:42 pm
YTZ
-
SEA
18h 52m
2 stops
$554Air Canada
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 September.

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 5 days was to Toronto, at $449 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 5 days was $449.

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 $627 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 $627.

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 August and May, when the average cost of round-trip tickets is $165 and $159 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 Monday 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 14 weeks before departure.

Good to know

Low seasonMarch
Cheapest flight$163
Best time to beat the crowds with an average 32% drop in price.
Most popular time to fly with an average 37% increase in price.
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 12582 reviews
7.0Entertainment
7.8Comfort
8.5Crew
7.0Food
8.1Boarding
Airline reviews

Someone rebooked my Alaska flight to a much later Delta flight. Now I am sitting at the Seattle airport after a long international flight and have to wait another 4 hours even though I would have been able to catch my initial flight

2.0 MediocreAnonymous, Jun 2026
SEA - EUG
Read more Alaska Airlines reviews

Someone rebooked my Alaska flight to a much later Delta flight. Now I am sitting at the Seattle airport after a long international flight and have to wait another 4 hours even though I would have been able to catch my initial flight

Very short leg - too short for any meals/snacks or entertainment.

We missed the flight. I had a passport issue and told the check in desk that I’m trying to resolve it but when I got approved for entry to USA at 3:32, one hour before departure, the employees had left the desk at 3:30. I tried calling and texting the numbers on the sign. No luck. Waited till the agents came back and couldn’t get a flight to our destination or close, so we flew to Las Vegas instead and drove 6 hrs to San Diego where I missed one night’s stay and the car rental that was reserved there. Extra car rental and hotel in Las Vegas was over $300. Lost tine and money. I wanted to extend the trip by two days but the $1600 SAVER fare wouldn’t let me make changes. Hours on the phone to find out there are no exceptions and no credit if cancelled in advance. Very disappointed. My son’s first vacation with me in 17 years. Wasted a lot of money. Next time I will use a local travel agent.

Booked a first class ticket and was not even offered a bottle of water…or a cracker…absolutely zero in flight service on a 1 hour flight

The second leg of my trip left without me despite being my inbound transfer only a few minutes late. My friends told the gate agent and they closed the doors and left early anyway. Then they tried to rebook me on a flight SIX hours later which only changed when I got a supervisor to make it 4 hours later. The gate agent was nasty, unhelpful, and walked away from me.

Well to start the crew is Seattle told me my luggage would go right thru to Ottawa. Not so before landing we were told to pick up luggage at carousel 8. On landing I asked and was told to pick it up & take it to the conveyer to be sent to Porter. Staff said Alaska always says that but no it doesn’t happen. As for Porter they said the flight would be a bit rough, so they offered a free wine or beer. Only snacks were provided on each flight.

Boarding was late with no communication. Flight was over an hour late with virtually no communication or updates. The app showed we had departed and were scheduled to arrive on time even though we sat on the tarmac for nearly an hour. People who were using the app to track our progress to pick us up were given erroneous information. Flight attendant was snooty when asked why app was showing us as delayed and arriving on time even though we had not left and ultimate’s not leave for over an hour. Just poor and arrogant.

My luggage was lost and doesn’t appear to be arrived any time soon.

Check in was a nightmare. We had about 15 people ahead of us but were in line for 45 minutes for priority passengers. Two people were checking in dogs and it took them forever. They even took the dogs out of the kennels to weigh them separately. Crazy! Then when we reached the front of the check in line we were told they couldn’t check us in because we were too early. Had to wait 19 minutes to check in and then check ourselves in and get back in line to drop our bags. This was first class! If I can avoid it I will never fly Alaska again. I sure didn’t get what I paid for.

It would have Bern better if the flight was on time.

My flight was delayed by 4 hours in 30 minute increments. The gate agents were amazing but the communication was not. We were told that there was a maintenance issue but they didn't know what it was. That didn't inspire confidence. Then they said they found it and it was fixed and the pilot just needed to sign off. Then the pilot needed to talk to the other pilot from the arriving flight and we'd be fine. Then we were waiting for the pilot to call back. Then the maintenance issue wasn't fixed. Then they decided we were getting a new plane (why didn't they decide this earlier??). Fine. But then they announced we were changing gates AND terminals. And we were boarding in 20 minutes. So we all had to run to the new terminal gate. We could have taken off at that time, but we then had to wait for all the people who rebooked on a different flight to book this flight again. That took 30+ minutes because there was only one gate agent. When everyone ditched this flight, I saw it as an opportunity to upgrade to comfort. Delta, the greedy jerks they are, charged me $121. After their delay, their fault, their issues, couldn't even discount an upgrade. They only handed out $12 meal vouchers for the delay. I can't even get a snack from starbucks for that.

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.

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

The Boarding process was great. Particularly since my wife and I require assistance. The flight attendants were amazing. We travel frequently; they honestly were a cut above. 😀

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.

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

Terrible experience delays going there and delays coming back will not be flying delta

Our flight was delayed several Times due to mechanical issues. Although I understand this may happen at times, it was very inconvenient and we had to book a hotel for an overnight stay. We were traveling with my 3-yo grandson and waiting at the airport from noon until 6:30pm with no reassurance that our next rescheduled flight would depart, we had to decide what’s best for him. A day later, I found out that I may be able to demand compensation if my flight is delayed more than 4 hours. I will hav to read the fine print next time.

Very comfortable seating and the Flight staff were very attentive. The premium economy section that I was seated in was very clean, updated, and well appointed. I would highly recommend flying United Airlines as this experience was better than the Japan Airlines business class that I flew several months ago.

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

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

Delayed by 2.5hrs any longer and they would’ve had to honour their own policy for breaking their own rules and regs. Not cool, especially when I have an infant child that needs to stay on a routine and they get schedules.

They had three choices for snacks - but you could only have one - and they ran out of the dark chocolate before they made it all the way down the aisle... Packed flight - limited service.

They opened my checked bag and even though my lock was tsa approved, they loose my lock and left my bag just like that. Incompetent people, very upset about it. I’ll try to avoid traveling with united

We fly to Ecuador frequently. Checking in is usually a hassle because most United agents take some time before they can verify that my passport doesn't require a visa to Ecuador. This time the process was even longer due to the cyber attack. But she was really nice to us. So glad we brought plenty of snacks to supplement the 3 flights from SEA to GYE.

We had selected seats in the app that were a 2x2 format in the middle of the plane. Our seats when we got on the plane had been moved to the back rows in a 3x1 format. What’s the point of paying up for tickets that allow seat selection if the airline will just change them?

Both flights were late by about 30 minutes .. Other than that, everything was ok..

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 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.

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.

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.

Scrooge airlines spoiled my last chance at Christmas with my 95 and 92 year old folks. and rest of the family in Calgary. Ticket personnel would not let me on without a passport and I always visit Canada with my enhanced driver;s License when I travel from the US

Flight was on time. Online check in capabilities made things quick and easy. Zone boarding was enforced, which I appreciate. Everyone was not lining up ahead of their zone being called. Crew was professional and friendly.

The big lady was sitting right next to me and the button to recline my seat was blocked by her huge arm. No power outlet for chargers. No inflight Wi-Fi movies

Westjet is the worst airline in the world, they are absolutely terrible, there are to many things that happened that I can't explain in this message, I would like to talk to someone about my ordeal. I am partial handicapped and that I can only walk a short distance, I calculated how far I walked and it was more than a kilometer, the pain is so bad today I have to go to my docor, they told me there was nobody available to take me to my gate, this is just one instance. This is not finished yet, I need to contact westjet and let them know about my trip from hell

They lost our luggage and didn’t return it until 15 days AFTER we got back.

The problem in part was with the airports, not really the fault of Air Canada. Confusing directions regarding the gate, in Seattle the recommended shuttle train entrance was not working. Simular problems in Toronto. Baggage arrived in good time. Marx Bros movie on entertainment from Seattle. I was told I was laughing too loudly, by the flight attendant. No lounge in Seattle. Lounge in Toronto excellent.

Both fights were delayed. Food could be better comparing to other international flights

I found the personal kind and caring. The Problem was not enough people to serve the the customers. The flow was restricted the crowd frustrated by the wait times. Air Canada seems to hire good people but they need backup in order to provide the service we pay for.

Flight late. Chaos at checkin and boarding. Beyond that it was fine!

The flight was delayed multiple times and I arrived hours later than I thought. I also had to change my schedule.

This was a red eye return, so I doubt there would be anyway to make it better. Other than adding beds.

Lost my bag. My first ever flight with them that they forced me to gate check my bag on, due to them having a 30 year old plane with small carry on bins, and they lost my bag. Never again.

Everything else was good it would have been better if they served food considering it was a late night flight

Flight crew was great. We were on time. Movie selection was good. Food was not included but what I brought was fine. No complaints!

My flight was on time. People were pleasant and helpful. The flight was uneventful.

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

Information on your arrival and departure airports