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Cheap flights from Ontario to Seattle from C$ 184

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 25/2. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
18 Feb — 25 Feb1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Ontario to Seattle

Keep the following information in mind while searching for Ontario to Seattle flight deals. Data was last updated 19 January 2026.

Round-trip from

C$ 275

One-way from

C$ 184

Popular in

June

Cheapest in

February

Average price

C$ 543

Good round-trip deal

C$ 324 or less

Good one-way deal

C$ 265 or less
Alaska Airlines
  • Alaska Airlines
  • 7/3-14/3
  • Nonstop
  • 10h 13m total
  • Ontario to Seattle
Search Deals
WestJet
  • WestJet
  • 25/2
  • 1 total stop
  • 9h 34m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 9% potential increase in price (C$ 66 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (C$ 11 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals
Price to beat on a round-trip flight from Ontario to Seattle/Tacoma Intl.
Search Deals
Price to beat on a one-way flight from Ontario to Seattle/Tacoma Intl.
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Find flight deals from Ontario to Seattle

Enter your travel dates to find the best prices.

Cheapest flights from Ontario to Seattle
Explore the most affordable flight options available from Ontario to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 19 January 2026.

Sat 7/34:45 p.m.
YYZ
-
SEA
Nonstop5h 33m
Alaska Airlines
Sat 14/37:55 a.m.
SEA
-
YYZ
Nonstop4h 40m
Alaska Airlines
Deal found 17/1C$ 275
Thu 26/27:45 a.m.
YYZ
-
SEA
1 stop9h 34m
WestJet
Mon 2/33:10 p.m.
SEA
-
YYZ
2 stops11h 48m
WestJet
Deal found 19/1C$ 292
Sat 30/59:00 a.m.
YYZ
-
SEA
2 stops14h 28m
WestJet
Mon 1/67:05 a.m.
SEA
-
YYZ
2 stops10h 55m
WestJet
Deal found 18/1C$ 307
Sat 30/51:30 p.m.
YYZ
-
SEA
1 stop9h 58m
WestJet
Sat 6/67:05 a.m.
SEA
-
YYZ
2 stops10h 55m
WestJet
Deal found 16/1C$ 312
Fri 1/56:45 a.m.
YUL
-
SEA
1 stop9h 23m
WestJet
Wed 6/52:05 p.m.
SEA
-
YUL
1 stop7h 37m
WestJet
Deal found 18/1C$ 313
Fri 22/51:30 p.m.
YYZ
-
SEA
1 stop9h 58m
WestJet
Mon 25/52:05 p.m.
SEA
-
YYZ
2 stops12h 45m
WestJet
Deal found 17/1C$ 313
Sat 9/58:00 a.m.
YYZ
-
SEA
1 stop8h 08m
WestJet
Sun 17/57:05 a.m.
SEA
-
YYZ
2 stops10h 55m
WestJet
Deal found 19/1C$ 316
Thu 7/51:30 p.m.
YYZ
-
SEA
1 stop9h 58m
WestJet
Sat 16/57:05 a.m.
SEA
-
YYZ
1 stop8h 47m
WestJet
Deal found 19/1C$ 317
Wed 4/37:45 a.m.
YYZ
-
SEA
1 stop9h 34m
Multiple Airlines
Wed 11/37:55 a.m.
SEA
-
YYZ
Nonstop4h 40m
Multiple Airlines
Deal found 18/1C$ 319
Fri 8/56:45 a.m.
YYZ
-
SEA
2 stops9h 23m
WestJet
Mon 11/57:05 a.m.
SEA
-
YYZ
2 stops10h 55m
WestJet
Deal found 18/1C$ 320
Fri 8/56:45 a.m.
YYZ
-
SEA
2 stops9h 23m
WestJet
Fri 15/52:05 p.m.
SEA
-
YYZ
2 stops12h 45m
WestJet
Deal found 17/1C$ 321
Sat 2/56:00 a.m.
YKF
-
SEA
1 stop10h 08m
WestJet
Sun 10/52:05 p.m.
SEA
-
YKF
1 stop7h 40m
WestJet
Deal found 17/1C$ 323

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario 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 19 January 2026.
Use the filters below to find and compare flights from Ontario to Seattle that are best for you.

Fly from

Ontario

Fly to

Seattle

Route

Depart

Return

Price

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 30/5

12:00 p.m.-8:28 p.m.

2 stops11h 28m

Seattle/Tacoma Intl

Mon 1/6

7:05 a.m.-6:52 p.m.

1 stop8h 47m

C$ 309

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sat 2/5

6:00 a.m.-1:08 p.m.

1 stop10h 08m

Seattle/Tacoma Intl

Sun 10/5

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

1 stop7h 40m

C$ 323

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 11/3

4:45 p.m.-7:18 p.m.

Nonstop5h 33m

Seattle/Tacoma Intl

Mon 16/3

3:10 p.m.-5:58 a.m.

2 stops11h 48m

C$ 324

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 7/5

6:45 a.m.-1:08 p.m.

2 stops9h 23m

Seattle/Tacoma Intl

Sat 16/5

7:05 a.m.-5:22 p.m.

1 stop7h 17m

C$ 324

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Fri 15/5

6:00 a.m.-1:08 p.m.

1 stop10h 08m

Seattle/Tacoma Intl

Sat 23/5

7:05 a.m.-6:25 p.m.

1 stop8h 20m

C$ 337

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Sat 30/5

6:10 p.m.-1:08 p.m.

1 stop21h 58m

Seattle/Tacoma Intl

Mon 1/6

7:05 a.m.-5:10 p.m.

1 stop7h 05m

C$ 342

LondonSeattle

YXU - SEA

YXUSEA

London

Sat 2/5

8:00 p.m.-1:08 p.m.

1 stop20h 08m

Seattle/Tacoma Intl

Sat 9/5

7:05 a.m.-7:07 p.m.

1 stop9h 02m

C$ 349

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Sat 25/4

5:40 a.m.-1:08 p.m.

2 stops34h 28m

Seattle/Tacoma Intl

Mon 27/4

2:05 p.m.-12:40 a.m.

1 stop7h 35m

C$ 349

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Wed 13/5

6:10 p.m.-8:28 p.m.

1 stop29h 18m

Seattle/Tacoma Intl

Wed 20/5

7:05 a.m.-5:10 p.m.

1 stop7h 05m

C$ 351

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Sat 2/5

6:10 p.m.-1:08 p.m.

1 stop21h 58m

Seattle/Tacoma Intl

Sun 10/5

7:05 a.m.-5:10 p.m.

1 stop7h 05m

C$ 355

Flights are sorted by cheapest round-trip flights first.

Deals found on 18/1

Showing 1-10 of 60 results
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Best time to book a flight from Ontario to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Ontario 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 Ontario to Seattle

What is the cheapest month to book a flight from Region of Ontario to Seattle?

Currently, December is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 182). Flying from Region of Ontario to Seattle in August is currently the most expensive (average of C$ 310). 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 ON to SEA?

Find hourly flight availability from Ontario 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 19 January 2026.

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

Weekly flight availability from Region of Ontario to Seattle

Explore weekly flight availability from Ontario to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 19 January 2026.

The most flights from CAON to SEA are scheduled on a Friday (10 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (5 on average).

How much does it cost to fly round-trip from Region of Ontario to Seattle?

Related info for your journey

Find useful and relevant information for your journey from Ontario 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 Ontario?

    Located just 18.4 km from the city centre, Seattle/Tacoma Intl (SEA) is the airport most travelers will use when flying to Seattle from Ontario.

  • How long is the flight from Region of Ontario to Seattle?

    Departing from Region of Ontario to Seattle will take you 7h 50m. The distance from Region of Ontario to Seattle is about 3306 km. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the cheapest airlines to fly from Region of Ontario to Seattle one-way?

    For one-way options, check prices for WestJet. According to our data, you can fly for as low as C$ 177. Users have also found prices from C$ 195 and C$ 208 on Alaska Airlines and Air Canada, respectively.

  • What are the most popular routes from Region of Ontario to Seattle?

    The most popular route from Region of Ontario to Seattle is Toronto Pearson Intl - Seattle/Tacoma Intl. You may also consider Montreal Pierre Elliott Trudeau Intl - Seattle/Tacoma Intl or Hamilton - Seattle/Tacoma Intl.

  • What are the most reliable airlines from Region of Ontario to Seattle?

    No one likes to see their flight delayed. When booking a flight from Region of Ontario to Seattle consider choosing Qatar Airways (79%), Alaska Airlines (59%) or Hawaiian Airlines (59%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Region of Ontario to Seattle?

    Looking at all options, your cheapest flight can be booked for C$ 173. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 319 on average, our data indicates C$ 386 when flying from Region of Ontario to Seattle.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario 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.

  • What is the cheapest month to book a flight from Region of Ontario to Seattle?

    Currently, December is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 182). Flying from Region of Ontario to Seattle in August is currently the most expensive (average of C$ 310). 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

Travelling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
SeaTac
Mukilteo
Tacoma
Kent
Tukwila
Bothell
Cashmere
Olympia
Renton
Marysville
Lynnwood
Kirkland

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Alternative routes for Ontario to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from Ontario to Seattle

Discover the top 6 airlines that operate flights from Ontario 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 19 January 2026.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 128AverageC$ 400FlexibilityNo cancel feeOn-time60%
Search WestJet flights
DeltaCheapestC$ 255AverageC$ 493FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
United AirlinesCheapestC$ 267AverageC$ 487FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 274AverageC$ 465FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 324AverageC$ 548FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
Hawaiian AirlinesCheapestC$ 414AverageC$ 467FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights

Fly with Cheapflights

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How does Cheapflights help users find flights from Ontario to Seattle?

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Why should you use Cheapflights to find cheap flight tickets from Ontario to Seattle?

Millions of users choose and trust Cheapflights to book the best flight deals from Ontario to Seattle for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

Can Cheapflights find flights from Ontario to Seattle with no change fees?

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

Can Cheapflights notify me if prices for flights from Ontario to Seattle become cheaper?

Of course! You can now track prices for flights from Ontario to Seattle and get an alert from Cheapflights when they change. Have a valid email address ready and click the bell icon next to the flight deals above to set up your price alerts.

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