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$155+ Cheap flights from Region of Waterloo Intl (YKF) to Seattle (SEA)

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 1/25. Fares are subject to change and may not be available on all flights or dates of travel.
YKF — SEA
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
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Cheap flight deals from Region of Waterloo Intl to Seattle

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 December 12, 2025.

This WestJet deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/266:25 amYKF - SEA
2 stops17h 21mWestJet
Sat 12/277:45 pmSEA - YKF
2 stops30h 43mWestJet
Deal found 12/11$889
This Trip.com deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/186:20 amYKF - SEA
1 stop11h 00mWestJet
Mon 12/223:10 pmSEA - YKF
1 stop11h 18mWestJet
Deal found 12/11$896
This WestJet deal was found by Cheapflights users on 12/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/266:25 amYKF - SEA
2 stops27h 55mWestJet
Mon 12/293:10 pmSEA - YKF
1 stop11h 18mWestJet
Deal found 12/10$927
This oojo deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/136:20 amYKF - SEA
1 stop11h 20mWestJet
Mon 12/153:10 pmSEA - YKF
1 stop11h 18mWestJet
Deal found 12/11$953
This oojo deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/156:20 amYKF - SEA
1 stop11h 00mWestJet
Mon 12/223:10 pmSEA - YKF
1 stop11h 18mWestJet
Deal found 12/11$964
This WestJet deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/266:25 amYKF - SEA
1 stop10h 55mWestJet
Sun 12/289:25 amSEA - YKF
2 stops17h 03mWestJet
Deal found 12/11$967
This FlightHub deal was found by Cheapflights users on 12/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/306:20 amYKF - SEA
1 stop11h 00mWestJet
Sun 1/43:10 pmSEA - YKF
1 stop11h 18mWestJet
Deal found 12/10$1,083
This FlightHub deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/156:20 amYKF - SEA
1 stop11h 00mWestJet
Fri 1/23:10 pmSEA - YKF
1 stop11h 18mWestJet
Deal found 12/11$1,086
This Expedia deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/266:25 amYKF - SEA
1 stop8h 58mMultiple Airlines
Mon 12/293:10 pmSEA - YKF
1 stop11h 18mMultiple Airlines
Deal found 12/11$1,105

Find 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 December 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$230
(Trip.com)

One-way from

$155
(Kiwi.com)

Popular in

June

Cheapest in

February

Average price

$403
Provider with most accurate pricing for Toronto Region of Waterloo Intl-Seattle/Tacoma Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Toronto Region of Waterloo Intl-Seattle/Tacoma Intl flights.
Search Deals
From Toronto Region of Waterloo Intl to Seattle/Tacoma Intl
Search Deals
One-way flight from Toronto Region of Waterloo Intl to Seattle/Tacoma Intl
Search Deals
Highest demand for flights based on searches. 10% potential increase in price ($42 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($5 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

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 2,558,603 searches. Data last updated December 12, 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 5/22

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Mon 5/25

7:05 am-12:45 am

1 stop14h 40m

$230

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 4/30

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Thu 5/7

7:05 am-12:45 am

1 stop14h 40m

$231

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sat 4/18

6:20 am-2:31 pm

1 stop11h 11m

Seattle/Tacoma Intl

Mon 4/27

2:05 pm-12:45 am

1 stop7h 40m

$336

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Tue 6/2

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Tue 6/9

2:05 pm-12:45 am

1 stop7h 40m

$423

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Wed 6/3

6:00 am-1:08 pm

1 stop10h 08m

Seattle/Tacoma Intl

Tue 6/9

2:05 pm-12:45 am

1 stop7h 40m

$423

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 4/23

6:20 am-2:19 pm

1 stop10h 59m

Seattle/Tacoma Intl

Sat 5/9

7:05 am-12:45 am

1 stop14h 40m

$425

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 5/31

6:00 am-8:28 pm

1 stop17h 28m

Seattle/Tacoma Intl

Wed 6/10

2:05 pm-12:45 am

1 stop7h 40m

$433

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Wed 6/3

6:00 am-1:08 pm

1 stop10h 08m

Seattle/Tacoma Intl

Wed 6/10

2:05 pm-12:45 am

1 stop7h 40m

$435

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Mon 2/23

6:20 am-2:19 pm

1 stop10h 59m

Seattle/Tacoma Intl

Fri 2/27

3:10 pm-5:29 am

1 stop11h 19m

$482

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 1/25

7:05 am-2:20 pm

1 stop10h 15m

Seattle/Tacoma Intl

Sun 2/1

3:10 pm-5:29 am

1 stop11h 19m

$502

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/11

Showing 1-10 of 21 results
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Compare providers for flights from Region of Waterloo Intl to Seattle

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Region of Waterloo Intl to Seattle in December.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Toronto Region of Waterloo Intl Airport-Seattle flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Toronto Region of Waterloo Intl Airport-Seattle flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Toronto Region of Waterloo Intl Airport-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Toronto Region of Waterloo Intl Airport-Seattle flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Toronto Region of Waterloo Intl Airport-Seattle flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 December 12, 2025.

One of the essential ways to save on airfare from Toronto Region of Waterloo Intl Airport to Seattle is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the morning could potentially save you up to 57% on airfare.

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?

    For a flight from Toronto Region of Waterloo Intl to Seattle, you will be flying into Seattle/Tacoma Intl. Seattle/Tacoma Intl (SEA) is just 11.4 mi from the center of the city. Seattle/Tacoma Intl is the only Seattle airport and it handles 0 inbound flights from Toronto Region of Waterloo Intl per day. 0 airlines have flights to Seattle/Tacoma Intl from Toronto Region of Waterloo Intl on a regular basis.

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

    For as low as $230, WestJet can have you in Seattle from Toronto Region of Waterloo Intl Airport in 17h 28m. There are 2024 mi between Toronto Region of Waterloo Intl Airport and Seattle.

  • 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

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
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