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Cheap flights from Seattle to Toronto from C$ 231

SEA — YTO
8 Oct — 15 Oct1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Toronto are usually found in January or November, booked 79 days in advance, depart on a Thursday or Tuesday and return on a Friday

Cheap flight deals from Seattle to Toronto

Enter your travel dates to find the best prices.

Cheapest flights from Seattle to Toronto

Fri 23/107:35 p.m. -
1 stop8h 20m
Tue 27/1010:50 p.m. -
2 stops18h 50m
Deal found 4/9C$ 510
Sat 3/1010:30 a.m. -
1 stop9h 15m
Sat 10/108:00 p.m. -
1 stop16h 40m
Deal found 6/9C$ 511
Fri 9/107:35 p.m. -
2 stops9h 25m
Thu 15/1012:00 p.m. -
1 stop9h 45m
Deal found 5/9C$ 513
Fri 25/97:35 p.m. -
1 stop21h 15m
Mon 28/98:40 p.m. -
1 stop16h 00m
Deal found 4/9C$ 513
Fri 2/1010:30 a.m. -
1 stop7h 45m
Sat 10/1010:25 p.m. -
1 stop14h 15m
Deal found 3/9C$ 514
Tue 6/107:35 p.m. -
1 stop8h 20m
Sat 10/1010:00 a.m. -
1 stop26h 40m
Deal found 3/9C$ 516
Wed 7/1010:30 a.m. -
1 stop9h 15m
Sat 10/108:00 p.m. -
1 stop16h 40m
Deal found 3/9C$ 517
Sat 26/910:30 a.m. -
2 stops20h 15m
Thu 22/1012:40 p.m. -
2 stops9h 05m
Deal found 5/9C$ 520
Thu 24/910:30 a.m. -
1 stop11h 35m
Mon 28/911:10 p.m. -
2 stops13h 30m
Deal found 4/9C$ 521
Sun 13/122:30 p.m. -
2 stops12h 15m
Tue 29/127:30 a.m. -
1 stop9h 10m
Deal found 4/9C$ 522
Thu 17/122:30 p.m. -
2 stops12h 15m
Thu 31/127:30 a.m. -
1 stop9h 10m
Deal found 4/9C$ 524
Fri 18/97:35 p.m. -
2 stops14h 10m
Mon 28/98:00 p.m. -
1 stop25h 45m
Deal found 3/9C$ 525

Find flight deals from Seattle to Toronto

Round-trip from

C$ 510

One-way from

C$ 231

Popular in

July

Cheapest in

January

Average price

C$ 802

Good round-trip deal

C$ 695 or less

Good one-way deal

C$ 385 or less
WestJet
  • WestJet
  • 23/10-27/10
  • 3 total stops
  • 27h 10m total
  • Seattle to Toronto
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WestJet
  • WestJet
  • 8/10-31/12
  • 1 total stop
  • 9h 15m total
  • Seattle to Toronto
Search Deals
Highest demand for flights based on searches. 23% potential increase in price (C$ 251 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease (C$ 41 potential savings vs. average RT price).
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Average for round-trip flights in September 2026
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Price to beat on a round-trip flight from Seattle/Tacoma Intl to Toronto (YTO).
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Price to beat on a one-way flight from Seattle/Tacoma Intl to Toronto (YTO).
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Cheapflights Fare Finder

 
Use the filters below to find and compare flights from Seattle to Toronto that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleHamilton

SEA Seattle/Tacoma Intl - YHM Hamilton

SEAYHM

Seattle/Tacoma Intl

Tue 15/9

10:30 a.m.-5:15 p.m.

1 stop27h 45m

Hamilton

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 250

SeattleHamilton

SEA Seattle/Tacoma Intl - YHM Hamilton

SEAYHM

Seattle/Tacoma Intl

Thu 24/9

7:35 p.m.-5:15 p.m.

1 stop18h 40m

Hamilton

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 253

SeattleToronto

SEA Seattle/Tacoma Intl - YKF Toronto Region of Waterloo Intl

SEAYKF

Seattle/Tacoma Intl

Fri 18/9

7:35 p.m.-7:50 p.m.

1 stop21h 15m

Toronto Region of Waterloo Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 253

SeattleToronto

SEA Seattle/Tacoma Intl - YKF Toronto Region of Waterloo Intl

SEAYKF

Seattle/Tacoma Intl

Tue 29/9

7:35 p.m.-7:50 p.m.

1 stop21h 15m

Toronto Region of Waterloo Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 254

SeattleHamilton

SEA Seattle/Tacoma Intl - YHM Hamilton

SEAYHM

Seattle/Tacoma Intl

Sat 19/9

7:35 p.m.-5:15 p.m.

1 stop18h 40m

Hamilton

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 257

SeattleHamilton

SEA Seattle/Tacoma Intl - YHM Hamilton

SEAYHM

Seattle/Tacoma Intl

Thu 17/9

7:35 p.m.-5:15 p.m.

1 stop18h 40m

Hamilton

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 258

SeattleToronto

SEA Seattle/Tacoma Intl - YKF Toronto Region of Waterloo Intl

SEAYKF

Seattle/Tacoma Intl

Sat 19/9

7:35 p.m.-7:50 p.m.

1 stop21h 15m

Toronto Region of Waterloo Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 263

SeattleToronto

SEA Seattle/Tacoma Intl - YKF Toronto Region of Waterloo Intl

SEAYKF

Seattle/Tacoma Intl

Thu 17/9

7:35 p.m.-7:50 p.m.

1 stop21h 15m

Toronto Region of Waterloo Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 264

SeattleHamilton

SEA Seattle/Tacoma Intl - YHM Hamilton

SEAYHM

Seattle/Tacoma Intl

Sun 27/9

10:30 a.m.-5:15 p.m.

1 stop27h 45m

Hamilton

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 270

SeattleToronto

SEA Seattle/Tacoma Intl - YKF Toronto Region of Waterloo Intl

SEAYKF

Seattle/Tacoma Intl

Fri 25/9

7:35 p.m.-7:50 p.m.

1 stop21h 15m

Toronto Region of Waterloo Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 270

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/9

Showing 1-10 of 60 resultsSorted by cheapest first
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Best time to book a flight from Seattle to Toronto

Have a flexible travel schedule? Discover the best time to fly to Toronto from Seattle with our price prediction graph.
Estimated round-trip price

Cheapflights Insights

Everything you need to know about your flight from Seattle to Toronto

What is the cheapest month to book a flight from Seattle to Toronto?

Currently, January is the cheapest month in which you can book a flight from Seattle to Toronto (average of C$ 352). Flying from Seattle to Toronto in July is currently the most expensive (average of C$ 829). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to YTO?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to Toronto as you normally would.

How much does it cost to fly round-trip from Seattle to Toronto?

Airfare is below average for this route at the moment.
Seattle to Toronto flights typically cost between C$ 550 and C$ 969 in October.
The cheapest round-trip price found within the last 5 days was C$ 510 on WestJet (23 Oct-27 Oct).

What’s the top layover airport for flights from Seattle to Toronto?

Calgary (YYC) – chosen by Cheapflights users on 75% of one-stop itineraries from Seattle to Toronto on Cheapflights.

What’s the cheapest layover airport for flights from Seattle to Toronto?

Calgary (YYC) is the most affordable 1-stop option, with an average round-trip price of C$ 377.

What’s the fastest layover option from Seattle to Toronto?

Flights via Calgary (YYC) have the shortest average one-way travel time for 1-stop routes: 7h 10m.

Which airport typically offers the quickest layover for flights from Seattle to Toronto?

Flights via Calgary (YYC) offer the fastest connection on this route, with an average layover time of 1h 43m.

How far ahead should I book a flight from Seattle to Toronto?

Booking 59 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Toronto. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

Reviews of airlines servicing Toronto

See what other customers who have flown with Alaska Airlines,WestJet, andAir Canada from Seattle to Toronto have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
7.9
Good
12,894 reviews
Check prices

Comfort

7.8

Food

7.0

Boarding

8.1

Entertainment

7.0

Overall

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Jul 2026

SEA - LHR

Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle
Alaska Airlines
7.9
Good
12,894 reviews
Alaska Airlines
7.9
Good
12,894 reviews
Check prices

Comfort

7.8

Food

7.0

Boarding

8.1

Entertainment

7.0

Overall

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Jul 2026

SEA - LHR

Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle
WestJet
7.2
Good
3,447 reviews
Alaska Airlines
7.9
Good
12,894 reviews
Check prices

Comfort

7.8

Food

7.0

Boarding

8.1

Entertainment

7.0

Overall

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Jul 2026

SEA - LHR

Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle
Air Canada
7.1
Good
11,601 reviews
Alaska Airlines
7.9
Good
12,894 reviews
Check prices

Comfort

7.8

Food

7.0

Boarding

8.1

Entertainment

7.0

Overall

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Jul 2026

SEA - LHR

Alaska has a brilliant crew. And the seats are good. As much as i loved my trip from Heathrow to Seattle, i definitely did not feel the same on the return flight. A lot was due to feeling very cramped and unfortunately for me, i had a kicker behind me and a passenger who did not stop moving (but constantly) next to me. The good was not good and i noticed that most people around me left most of their meal. The ice cream was very nice. I did not have breakfast. However the food was very nice on the way to Seattle

Related info for your journey

  • What airport do you fly from for flights from Seattle to Toronto?

    Seattle/Tacoma Intl (SEA), located 18.4 km from the city centre, is the airport you fly out of when you book flights from Seattle to Toronto. 3 airlines have flights from Seattle/Tacoma Intl to Toronto on a regular basis. Booking flights from Seattle/Tacoma Intl to Toronto should not be difficult; the airport handles an average of 0 outbound flights to Toronto per day.

  • How long is the flight from Seattle to Toronto?

    For as low as C$ 717, WestJet can have you in Toronto from Seattle in 4h 46m. Airlines will cover a distance of 3306 km. Both multi-stop and direct flights can be found to your destination and back.

  • What are the cheapest airlines flying from Seattle to Toronto round-trip?

    According to our current data, Alaska Airlines (C$ 281), WestJet (C$ 285), and Air Canada (C$ 365) offers the cheapest pricing from Seattle to Toronto. You may be able to fly from Seattle to Toronto for 53% less than the average price by searching for these airlines.

  • What are the cheapest airlines to fly from Seattle to Toronto one-way?

    For one-way options, check prices for Alaska Airlines. According to our data, you can fly for as low as C$ 113. Users have also found prices from C$ 138 and C$ 144 on Air Canada and WestJet, respectively.

  • What are the most popular routes from Seattle to Toronto?

    Most travellers choose Seattle/Tacoma Intl - Toronto Pearson Intl, Seattle/Tacoma Intl - Toronto Island or Seattle/Tacoma Intl - Hamilton when deciding on the best route from Seattle to Toronto.

  • What are the most reliable airlines from Seattle to Toronto?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to Toronto on time: Qatar Airways (95%), Alaska Airlines (95%), Air Canada (89%).

  • What are the cheapest flights from Seattle to Toronto?

    On average you can expect to pay C$ 752 for a flight from Seattle to Toronto. The cheapest flight overall is C$ 224 while the most popular route, (Seattle/Tacoma Intl - Toronto Pearson Intl) is currently priced at C$ 522.

  • Can I find deals for flights from Seattle to Toronto that include hotel bookings?

    Yes. In addition to deals on Seattle to Toronto flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Toronto?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Toronto.

  • Can I find deals for business class flights from Seattle to Toronto?

    Yes. Cheapflights offers flight deals from Seattle to Toronto by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to Toronto?

    Currently, January is the cheapest month in which you can book a flight from Seattle to Toronto (average of C$ 352). Flying from Seattle to Toronto in July is currently the most expensive (average of C$ 829). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Top 3 airlines flying from Seattle to Toronto

AirlineCheapestAverageFlexibilityOn-time
Alaska AirlinesCheapestC$ 281AverageC$ 772FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
WestJetCheapestC$ 285AverageC$ 523FlexibilityNo cancel feeOn-time60%
Search WestJet flights
Air CanadaCheapestC$ 365AverageC$ 746FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

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Need flexible booking options for your flight to Toronto from Seattle? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

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Yes, Cheapflights has a feature called Price Alert, which notifies users when flight prices change. Track prices for your flight to Toronto from Seattle today and book when prices fit your budget.

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