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Cheap flights from Toronto Region of Waterloo Intl Airport to Seattle from $152

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 4/29. 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

Enter your travel dates to find the best prices.
WestJet Logo
6:00 am - 8:28 pm
YKF
-
SEA
17h 28m1 stop
WestJet Logo
7:05 am - 12:45 am
SEA
-
YKF
14h 40m1 stop
$229WestJet
Fri, May 1 - Thu, May 7
WestJet Logo
6:20 am - 2:20 pm
YKF
-
SEA
11h 00m1 stop
WestJet Logo
3:10 pm - 5:28 am
SEA
-
YKF
11h 18m1 stop
$232WestJet
Mon, Jan 12 - Wed, Jan 14
WestJet Logo
6:20 am - 2:19 pm
YKF
-
SEA
10h 59m1 stop
WestJet Logo
3:10 pm - 5:29 am
SEA
-
YKF
11h 19m1 stop
$233WestJet
Thu, Mar 5 - Sun, Mar 8
WestJet Logo
6:00 am - 1:08 pm
YKF
-
SEA
10h 08m1 stop
WestJet Logo
7:05 am - 12:45 am
SEA
-
YKF
14h 40m1 stop
$234WestJet
Wed, May 13 - Wed, May 20
WestJet Logo
6:20 am - 2:20 pm
YKF
-
SEA
11h 00m1 stop
WestJet Logo
3:10 pm - 5:28 am
SEA
-
YKF
11h 18m1 stop
$239WestJet
Thu, Jan 22 - Sun, Jan 25
WestJet Logo
6:00 am - 8:28 pm
YKF
-
SEA
17h 28m1 stop
WestJet Logo
7:05 am - 12:45 am
SEA
-
YKF
14h 40m1 stop
$247WestJet
Sat, May 23 - Tue, Jun 2
WestJet Logo
7:00 pm - 1:19 pm
YKF
-
SEA
21h 19m1 stop
WestJet Logo
3:10 pm - 5:29 am
SEA
-
YKF
11h 19m1 stop
$296WestJet
Sat, Mar 7 - Wed, Mar 11
Multiple Airlines Logo
7:05 am - 2:20 pm
YKF
-
SEA
10h 15m1 stop
Multiple Airlines Logo
3:10 pm - 5:28 am
SEA
-
YKF
11h 18m1 stop
$317Multiple Airlines
Thu, Jan 22 - Sun, Jan 25
Multiple Airlines Logo
7:05 am - 2:20 pm
YKF
-
SEA
10h 15m1 stop
Multiple Airlines Logo
11:55 am - 5:28 am
SEA
-
YKF
14h 33m2 stops
$322Multiple Airlines
Thu, Jan 22 - Sun, Jan 25
WestJet Logo
6:20 am - 2:20 pm
YKF
-
SEA
11h 00m1 stop
WestJet Logo
11:55 am - 5:28 am
SEA
-
YKF
14h 33m2 stops
$326WestJet
Thu, Jan 22 - Sun, Jan 25

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
May 1
YKF6:00 amToronto Region of Waterloo Intl
17h 28m
1 stop
SEA8:28 pmSeattle/Tacoma Intl
May 7
SEA7:05 amSeattle/Tacoma Intl
14h 40m
1 stop
YKF12:45 amToronto Region of Waterloo Intl
$229
Find similar
WestJet
Mar 5
YKF6:20 amToronto Region of Waterloo Intl
10h 59m
1 stop
SEA2:19 pmSeattle/Tacoma Intl
Mar 8
SEA3:10 pmSeattle/Tacoma Intl
11h 19m
1 stop
YKF5:29 amToronto Region of Waterloo Intl
$232
Find similar
WestJet
Mar 5
YKF6:20 amToronto Region of Waterloo Intl
10h 59m
1 stop
SEA2:19 pmSeattle/Tacoma Intl
Mar 8
SEA3:10 pmSeattle/Tacoma Intl
11h 19m
1 stop
YKF5:29 amToronto Region of Waterloo Intl
$233
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 December 18, 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

Fri 5/1

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Thu 5/7

7:05 am-12:45 am

1 stop14h 40m

$229

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Mon 1/12

6:20 am-2:20 pm

1 stop11h 00m

Seattle/Tacoma Intl

Wed 1/14

3:10 pm-5:28 am

1 stop11h 18m

$232

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 3/5

6:20 am-2:19 pm

1 stop10h 59m

Seattle/Tacoma Intl

Sun 3/8

3:10 pm-5:29 am

1 stop11h 19m

$233

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Wed 5/13

6:00 am-1:08 pm

1 stop10h 08m

Seattle/Tacoma Intl

Wed 5/20

7:05 am-12:45 am

1 stop14h 40m

$234

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 1/22

6:20 am-2:20 pm

1 stop11h 00m

Seattle/Tacoma Intl

Sun 1/25

3:10 pm-5:28 am

1 stop11h 18m

$239

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sat 5/23

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Tue 6/2

7:05 am-12:45 am

1 stop14h 40m

$247

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sat 3/7

7:00 pm-1:19 pm

1 stop21h 19m

Seattle/Tacoma Intl

Wed 3/11

3:10 pm-5:29 am

1 stop11h 19m

$296

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 1/22

7:05 am-2:20 pm

1 stop10h 15m

Seattle/Tacoma Intl

Sun 1/25

3:10 pm-5:28 am

1 stop11h 18m

$317

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 1/22

7:05 am-2:20 pm

1 stop10h 15m

Seattle/Tacoma Intl

Sun 1/25

11:55 am-5:28 am

2 stops14h 33m

$322

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 1/22

6:20 am-2:20 pm

1 stop11h 00m

Seattle/Tacoma Intl

Sun 1/25

11:55 am-5:28 am

2 stops14h 33m

$326

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 Wednesday. momondo users have found tickets for Wednesday departures for as low as $422. 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 $682.

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 $274 when looking at flights departing in the evening. Flights to Seattle are more costly in the morning, with an average ticket price of $545. Departure times in the morning 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

Fastest flight time

10h 59m

Direct flights

None
The fastest flight from Toronto Region of Waterloo Intl Airport to Seattle takes 10h 59m
There are no direct flights from Toronto Region of Waterloo Intl Airport to Seattle. There are no popular flight routes from Toronto Region of Waterloo Intl Airport to Seattle.
Search flight deals

  • 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 10h 59m.

  • 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
Tacoma
Leavenworth
SeaTac
Ocean Shores
Renton
Olympia
Lynnwood
Kent
Marysville
Puyallup
Redmond
Tukwila
Cle Elum
Federal Way
Lakewood
Fife
Centralia
Westport
Kirkland
Shoreline

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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