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Cheap flights from Toronto Region of Waterloo Intl Airport to Seattle from $135

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Toronto Region of Waterloo Intl Airport to Seattle departing on 8/27. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Toronto Region of Waterloo Intl Airport to Seattle

Cheap round-trip flights

WestJet Logo
6:00 am - 12:58 pmYKF-SEA
9h 58m1 stop
WestJet Logo
7:05 am - 6:56 pmSEA-YKF
8h 51m1 stop
$248WestJet
Find Deal
Tue, Aug 26 - Thu, Aug 28
WestJet Logo
6:00 am - 8:28 pmYKF-SEA
17h 28m1 stop
WestJet Logo
1:50 pm - 12:46 amSEA-YKF
7h 56m1 stop
$269WestJet
Find Deal
Sun, Aug 24 - Wed, Aug 27
WestJet Logo
6:00 am - 12:58 pmYKF-SEA
9h 58m1 stop
WestJet Logo
1:50 pm - 12:46 amSEA-YKF
7h 56m1 stop
$270WestJet
Find Deal
Tue, Aug 26 - Wed, Aug 27
WestJet Logo
6:00 am - 12:58 pmYKF-SEA
9h 58m1 stop
WestJet Logo
1:50 pm - 12:45 amSEA-YKF
7h 55m1 stop
$291WestJet
Find Deal
Sun, Aug 31 - Thu, Sep 4
WestJet Logo
6:00 am - 8:28 pmYKF-SEA
17h 28m1 stop
WestJet Logo
8:40 am - 12:46 amSEA-YKF
13h 06m1 stop
$300WestJet
Find Deal
Fri, Aug 29 - Sun, Aug 31
Logo
6:15 am - 12:33 pmYKF-SEA
9h 18m1 stop
Logo
2:55 pm - 5:30 amSEA-YKF
11h 35m2 stops
$301
Find Deal
Sun, Sep 21 - Tue, Sep 30
Logo
6:15 am - 8:29 pmYKF-SEA
17h 14m2 stops
Logo
2:55 pm - 5:30 amSEA-YKF
11h 35m2 stops
$317
Find Deal
Sun, Sep 21 - Tue, Sep 30
WestJet Logo
6:00 am - 8:28 pmYKF-SEA
17h 28m1 stop
WestJet Logo
1:50 pm - 12:45 amSEA-YKF
7h 55m1 stop
$330WestJet
Find Deal
Sun, Aug 24 - Thu, Sep 4
WestJet Logo
6:00 am - 12:59 pmYKF-SEA
9h 59m1 stop
WestJet Logo
1:50 pm - 12:45 amSEA-YKF
7h 55m1 stop
$348WestJet
Find Deal
Mon, Oct 13 - Thu, Oct 16
WestJet Logo
6:00 am - 12:59 pmYKF-SEA
9h 59m1 stop
WestJet Logo
1:50 pm - 12:45 amSEA-YKF
7h 55m1 stop
$354WestJet
Find Deal
Tue, Sep 16 - Wed, Oct 15

WestJet flights from Toronto Region of Waterloo Intl Airport to Seattle

Our best WestJet deals on Toronto Region of Waterloo Intl Airport to Seattle flight tickets
WestJet
Aug 26
YKF6:00 amToronto Region of Waterloo Intl
9h 58m
1 stop
SEA12:58 pmSeattle/Tacoma Intl
Aug 28
SEA7:05 amSeattle/Tacoma Intl
8h 51m
1 stop
YKF6:56 pmToronto Region of Waterloo Intl
$248
Find similar
WestJet
Aug 24
YKF6:00 amToronto Region of Waterloo Intl
17h 28m
1 stop
SEA8:28 pmSeattle/Tacoma Intl
Aug 27
SEA1:50 pmSeattle/Tacoma Intl
7h 56m
1 stop
YKF12:46 amToronto Region of Waterloo Intl
$269
Find similar
WestJet
Aug 26
YKF6:00 amToronto Region of Waterloo Intl
9h 58m
1 stop
SEA12:58 pmSeattle/Tacoma Intl
Aug 27
SEA1:50 pmSeattle/Tacoma Intl
7h 56m
1 stop
YKF12:46 amToronto Region of Waterloo Intl
$270
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Toronto Region of Waterloo Intl Airport to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated August 3, 2025.
Use the filters below to find and compare flights from Toronto Region of Waterloo Intl Airport to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Tue 8/26

6:00 am-12:58 pm

1 stop9h 58m

Seattle/Tacoma Intl

Thu 8/28

7:05 am-6:56 pm

1 stop8h 51m

$248

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 8/24

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Wed 8/27

1:50 pm-12:46 am

1 stop7h 56m

$269

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Tue 8/26

6:00 am-12:58 pm

1 stop9h 58m

Seattle/Tacoma Intl

Wed 8/27

1:50 pm-12:46 am

1 stop7h 56m

$270

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 8/31

6:00 am-12:58 pm

1 stop9h 58m

Seattle/Tacoma Intl

Thu 9/4

1:50 pm-12:45 am

1 stop7h 55m

$291

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Fri 8/29

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Sun 8/31

8:40 am-12:46 am

1 stop13h 06m

$300

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 9/21

6:15 am-12:33 pm

1 stop9h 18m

Seattle/Tacoma Intl

Tue 9/30

2:55 pm-5:30 am

2 stops11h 35m

$301

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 9/21

6:15 am-8:29 pm

2 stops17h 14m

Seattle/Tacoma Intl

Tue 9/30

2:55 pm-5:30 am

2 stops11h 35m

$317

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 8/24

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Thu 9/4

1:50 pm-12:45 am

1 stop7h 55m

$330

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Mon 10/13

6:00 am-12:59 pm

1 stop9h 59m

Seattle/Tacoma Intl

Thu 10/16

1:50 pm-12:45 am

1 stop7h 55m

$348

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Tue 9/16

6:00 am-12:59 pm

1 stop9h 59m

Seattle/Tacoma Intl

Wed 10/15

1:50 pm-12:45 am

1 stop7h 55m

$354

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Seattle from

How to get the cheapest flight ticket from Toronto Region of Waterloo Intl Airport to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to Seattle?

On average, the least expensive day to fly to Seattle from Toronto Region of Waterloo Intl Airport is on a Thursday. momondo users have found tickets for Thursday departures for as low as $439. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday is the most expensive day to depart from Toronto Region of Waterloo Intl Airport because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $649.

What is the cheapest time of day to depart on your flight to Seattle?

Flying to Seattle from Toronto Region of Waterloo Intl Airport in the evening is the least expensive time of day to depart. momondo users have found prices as low as $288 when looking at flights departing in the evening. Flights to Seattle are more costly at noon, with an average ticket price of $539. Departure times at noon fall within the peak daily travel times, which is why tickets can be more expensive.

When to book flights from Toronto Region of Waterloo Intl Airport to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from Toronto Region of Waterloo Intl Airport to Seattle according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Toronto Region of Waterloo Intl Airport to Seattle (YKF to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Toronto Region of Waterloo Intl Airport to Seattle

Best Price Found

$135

Fastest flight time

9h 18m

Direct flights

None

Airports in Seattle

1 airport
The best one-way flight to Seattle from Toronto Region of Waterloo Intl Airport in the past 72 hours is $135. The best round-trip flight deal from Toronto Region of Waterloo Intl Airport to Seattle found on momondo in the last 72 hours is $248.
The fastest flight from Toronto Region of Waterloo Intl Airport to Seattle takes 9h 18m
There are no direct flights from Toronto Region of Waterloo Intl Airport to Seattle. Popular non-direct route for this connection is Toronto Region of Waterloo Intl Airport - Seattle/Tacoma Intl Airport.
There is 1 airport near Seattle: Seattle/Tacoma Intl (SEA)
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  • How far is Toronto Region of Waterloo Intl to Seattle/Tacoma Intl by plane?

    Seattle/Tacoma Intl is 2024.0 mi away from Toronto Region of Waterloo Intl. A reasonable flight in good conditions will take 9h 18m.

  • When did momondo last update prices for flights from Toronto Region of Waterloo Intl Airport to Seattle/Tacoma Intl Airport?

    Prices for flights from Toronto Region of Waterloo Intl Airport to Seattle/Tacoma Intl Airport are refreshed on a daily basis.

  • How old do you have to be to fly from Toronto Region of Waterloo Intl Airport to Seattle/Tacoma Intl Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Toronto Region of Waterloo Intl Airport to Seattle/Tacoma Intl Airport.

  • What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

    The travel and health documents you'll need for your trip to Seattle/Tacoma Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
Tacoma
SeaTac
Ocean Shores
Olympia
Renton
Kent
Federal Way
Puyallup
Lynnwood
Marysville
Tukwila
Kirkland
Lakewood
Fife
Centralia
Cle Elum
Shoreline
Westport
Redmond

Why use momondo?

Why should I use momondo to find a flight deal from Toronto to Seattle?

It is quick and easy to find Toronto to Seattle flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Seattle that suits you.

Can I find flights from Toronto to Seattle with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Toronto to Seattle flights to just show those with flexible booking policies.

How can momondo help me find flights from Toronto to Seattle?

Once you have performed a search for Toronto to Seattle flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Toronto to Seattle right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to Seattle from Toronto. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

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