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Cheap flights from Toronto Region of Waterloo Intl Airport to Seattle from C$ 241

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 18/11. Fares are subject to change and may not be available on all flights or dates of travel.
YKF — SEA
27 Nov — 4 Dec1
1 adult
1 adult, Economy, 0 bags

Find flight deals from Region of Waterloo Intl to Seattle

Enter your travel dates to find the best prices.

Cheapest flights from Region of Waterloo Intl to Seattle
Explore the most affordable flight options available from Region of Waterloo Intl to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 28 October 2025.

Mon 24/116:20 a.m.YKF - SEA
1 stop11h 00mWestJet
Fri 5/123:10 p.m.SEA - YKF
1 stop11h 18mWestJet
Deal found 26/10C$ 438
Thu 20/117:05 a.m.YKF - SEA
1 stop10h 15mMultiple Airlines
Sun 23/113:10 p.m.SEA - YKF
1 stop11h 18mMultiple Airlines
Deal found 25/10C$ 464
Thu 20/116:20 a.m.YKF - SEA
1 stop11h 00mWestJet
Sun 23/113:10 p.m.SEA - YKF
1 stop11h 18mWestJet
Deal found 25/10C$ 469
Sun 23/117:05 a.m.YKF - SEA
1 stop10h 15mMultiple Airlines
Sun 30/1111:55 a.m.SEA - YKF
2 stops14h 33mMultiple Airlines
Deal found 25/10C$ 488
Mon 10/116:20 a.m.YKF - SEA
1 stop11h 00mWestJet
Fri 14/113:10 p.m.SEA - YKF
1 stop11h 18mWestJet
Deal found 27/10C$ 601
Mon 10/116:20 a.m.YKF - SEA
1 stop11h 00mWestJet
Sun 16/113:10 p.m.SEA - YKF
1 stop11h 18mWestJet
Deal found 27/10C$ 723
Thu 18/126:20 a.m.YKF - SEA
1 stop11h 00mWestJet
Mon 22/123:10 p.m.SEA - YKF
1 stop11h 18mWestJet
Deal found 27/10C$ 738

Cheap flight deals from Region of Waterloo Intl to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Region of Waterloo Intl (YKF) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 28 October 2025.

Round-trip from

C$ 336

One-way from

C$ 241

Popular in

November

Cheapest in

May

Average price

C$ 396
WestJet
  • WestJet
  • 17/3-23/3
  • 2 total stops
  • 22h 18m total
  • Toronto to Seattle
Search Deals
WestJet
  • WestJet
  • 18/11
  • 1 total stop
  • 11h 00m total
  • Toronto to Seattle
Search Deals
Highest demand for flights based on searches. 34% potential increase in price (C$ 318 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 21% potential price decrease (C$ 108 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Region of Waterloo Intl 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, Cheapflights users made 629,999 searches. Data last updated 28 October 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

Region of Waterloo Intl

Fly to

Seattle

Route

Depart

Return

Price

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Fri 20/2

7:05 a.m.-10:21 a.m.

2 stops30h 16m

Seattle/Tacoma Intl

Sun 22/2

3:10 p.m.-5:29 a.m.

1 stop11h 19m

C$ 508

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 5/2

7:05 a.m.-10:21 a.m.

2 stops30h 16m

Seattle/Tacoma Intl

Mon 9/2

11:55 a.m.-5:29 a.m.

2 stops14h 34m

C$ 524

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 5/2

6:20 a.m.-10:21 a.m.

3 stops31h 01m

Seattle/Tacoma Intl

Mon 9/2

11:55 a.m.-5:29 a.m.

2 stops14h 34m

C$ 547

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Mon 10/11

6:20 a.m.-2:20 p.m.

1 stop11h 00m

Seattle/Tacoma Intl

Fri 14/11

3:10 p.m.-5:28 a.m.

1 stop11h 18m

C$ 601

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Tue 17/3

6:20 a.m.-2:19 p.m.

1 stop10h 59m

Seattle/Tacoma Intl

Mon 23/3

11:55 a.m.-5:29 a.m.

2 stops14h 34m

C$ 639

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 2/4

6:20 a.m.-2:19 p.m.

1 stop10h 59m

Seattle/Tacoma Intl

Thu 30/4

2:05 p.m.-12:45 a.m.

1 stop7h 40m

C$ 691

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 18/12

6:20 a.m.-2:20 p.m.

1 stop11h 00m

Seattle/Tacoma Intl

Mon 22/12

3:10 p.m.-5:28 a.m.

1 stop11h 18m

C$ 738

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Tue 23/12

6:20 a.m.-2:20 p.m.

1 stop11h 00m

Seattle/Tacoma Intl

Wed 31/12

3:10 p.m.-5:28 a.m.

1 stop11h 18m

C$ 786

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sat 28/2

7:00 p.m.-2:19 p.m.

1 stop22h 19m

Seattle/Tacoma Intl

Tue 3/3

5:40 p.m.-5:29 a.m.

2 stops32h 49m

C$ 792

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Tue 18/11

6:20 a.m.-2:20 p.m.

1 stop11h 00m

C$ 241

Flights are sorted by cheapest round-trip flights first.

Deals found on 27/10

Showing 1-10 of 17 results
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Best time to book a flight from Region of Waterloo Intl to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Region of Waterloo Intl with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Toronto Region of Waterloo Intl Airport to Seattle

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

Find hourly flight availability from Region of Waterloo Intl to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 28 October 2025.

It’s typically best to fly out from Toronto Region of Waterloo Intl Airport to Seattle in the afternoon. Doing so could potentially save you 56% on the flight price compared to flying at noon, which is usually more expensive.

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated 28 October 2025.
Read through reviews of airlines operating flights from Toronto Region of Waterloo Intl Airport to Seattle, such as WestJet. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
WestJet
7.2
Good
3,148 reviews
Check prices

Boarding

7.4

Comfort

7.1

Crew

7.9

Entertainment

6.1

Food

6.2

Overall

7.2

Reviews

1 / 20
6.0
Good

Deb,Jan 2025

YYZ - YYC

Boarding went smoothly, you didn't accept debit card for food on flight
WestJet
7.2
Good
3,148 reviews
WestJet
7.2
Good
3,148 reviews
Check prices

Boarding

7.4

Comfort

7.1

Crew

7.9

Entertainment

6.1

Food

6.2

Overall

7.2

Reviews

1 / 20
6.0
Good

Deb,Jan 2025

YYZ - YYC

Boarding went smoothly, you didn't accept debit card for food on flight

Related info for your journey

Find useful and relevant information for your journey from Region of Waterloo Intl to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from Toronto Region of Waterloo Intl?

    Seattle/Tacoma Intl (SEA) is the airport you will fly into if you book a flight from Toronto Region of Waterloo Intl to Seattle. You should not have trouble finding flights to Seattle/Tacoma Intl from Toronto Region of Waterloo Intl; the airport handles an average of 0 inbound flights from Toronto Region of Waterloo Intl per day. You should also have plenty of airline options to choose from since 1 airline has flights to the Seattle airport from Toronto Region of Waterloo Intl. It is only a 18.4 km journey from Seattle/Tacoma Intl (SEA) to Seattle’s city centre.

  • How long is the flight from Toronto Region of Waterloo Intl Airport to Seattle?

    Departing from Toronto Region of Waterloo Intl Airport to Seattle will take you 31h 01m. The distance between Toronto Region of Waterloo Intl Airport and Seattle is about 3257 km.

  • What is the cheapest airline to fly from Toronto Region of Waterloo Intl Airport to Seattle round-trip?

    WestJet, at C$ 185, was found to be the cheapest airline from Toronto Region of Waterloo Intl Airport to Seattle.. WestJet is priced at 57% lower than the current average price of a flight leaving 3 months from now.

  • Can I find deals for flights from Region of Waterloo Intl to Seattle that include hotel bookings?

    Yes. In addition to deals on Region of Waterloo Intl to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Region of Waterloo Intl to Seattle?

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

  • Can I find deals for business class flights from Region of Waterloo Intl to Seattle?

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

See more FAQs

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
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Renton
Olympia
Marysville
Lynnwood

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Top airline flying from Region of Waterloo Intl to Seattle

Discover the top airline that operate flights from Region of Waterloo Intl to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 629,999 searches. Data last updated 28 October 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 185AverageC$ 310FlexibilityNo cancel feeOn-time60%
Search WestJet flights

Fly with Cheapflights

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How does Cheapflights help users find flights from Region of Waterloo Intl to Seattle?

Deals for Region of Waterloo Intl to Seattle flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Region of Waterloo Intl to Seattle?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Region of Waterloo Intl to Seattle.

Can Cheapflights find flights from Region of Waterloo Intl to Seattle with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights from Region of Waterloo Intl to Seattle flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights from Region of Waterloo Intl to Seattle become cheaper?

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