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Cheap flights from Ontario to Seattle from C$ 209

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 21/10. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
29 Aug — 5 Sep1
1 adult

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 24 August 2025.

Round-trip from

C$ 312

One-way from

C$ 210

Popular in

December

Cheapest in

February

Average price

C$ 540

Good round-trip deal

C$ 453 or less

Good one-way deal

C$ 330 or less
WestJet
  • WestJet
  • 23/9-2/10
  • 2 total stops
  • 15h 31m total
  • Ontario to Seattle
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WestJet
  • WestJet
  • 7/10
  • 1 total stop
  • 9h 59m total
  • Ontario to Seattle
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High demand for flights, 5% potential price rise
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Cheapest flight prices on average. 1% potential price decrease (C$ 11 potential savings vs. average RT price).
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Average for round-trip flights in August 2025
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Price to beat on a round-trip flight from Ontario to Seattle/Tacoma Intl.
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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

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 24 August 2025.

Tue 23/98:00 a.m.YYZ - SEA
1 stop7h 59mWestJet
Thu 2/101:50 p.m.SEA - YYZ
1 stop7h 32mWestJet
Deal found 23/8C$ 312
Sun 12/106:45 a.m.YYZ - SEA
1 stop8h 48mWestJet
Mon 20/108:40 a.m.SEA - YYZ
2 stops12h 51mWestJet
Deal found 24/8C$ 314
Sun 12/106:45 a.m.YYZ - SEA
1 stop8h 48mWestJet
Sat 18/101:50 p.m.SEA - YYZ
1 stop7h 32mWestJet
Deal found 23/8C$ 315
Wed 17/912:00 p.m.YYZ - SEA
2 stops11h 29mWestJet
Wed 24/98:40 a.m.SEA - YYZ
1 stop7h 12mWestJet
Deal found 23/8C$ 321
Sat 18/1012:00 p.m.YYZ - SEA
2 stops10h 14mWestJet
Tue 21/107:05 a.m.SEA - YYZ
1 stop7h 17mWestJet
Deal found 23/8C$ 322
Thu 2/1012:25 p.m.YTZ - SEA
1 stop10h 06mAir Canada
Mon 6/107:15 a.m.SEA - YTZ
1 stop9h 34mAir Canada
Deal found 23/8C$ 323
Sun 28/96:45 a.m.YYZ - SEA
1 stop8h 50mWestJet
Fri 3/101:15 p.m.SEA - YYZ
1 stop8h 16mWestJet
Deal found 24/8C$ 323
Fri 21/119:00 a.m.YYZ - SEA
1 stop8h 26mAir Canada
Wed 26/1110:05 a.m.SEA - YYZ
1 stop7h 39mAir Canada
Deal found 22/8C$ 325
Wed 17/912:00 p.m.YYZ - SEA
2 stops11h 29mWestJet
Sun 21/91:15 p.m.SEA - YYZ
1 stop8h 16mWestJet
Deal found 24/8C$ 326
Fri 17/106:30 a.m.YYZ - SEA
1 stop9h 29mWestJet
Sun 19/108:40 a.m.SEA - YYZ
2 stops12h 51mWestJet
Deal found 24/8C$ 328
Thu 13/117:45 a.m.YYZ - SEA
1 stop9h 35mMultiple Airlines
Tue 18/117:55 a.m.SEA - YYZ
Nonstop4h 40mMultiple Airlines
Deal found 22/8C$ 329
Thu 6/119:00 a.m.YYZ - SEA
1 stop8h 26mAir Canada
Mon 10/118:00 p.m.SEA - YYZ
1 stop7h 24mAir Canada
Deal found 22/8C$ 333

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 24 August 2025.
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

Tue 23/9

8:00 a.m.-12:59 p.m.

1 stop7h 59m

Seattle/Tacoma Intl

Thu 2/10

1:50 p.m.-12:22 a.m.

1 stop7h 32m

C$ 312

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 12/10

6:45 a.m.-12:33 p.m.

1 stop8h 48m

Seattle/Tacoma Intl

Sat 18/10

1:50 p.m.-12:22 a.m.

1 stop7h 32m

C$ 315

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 17/10

4:45 p.m.-7:08 p.m.

Nonstop5h 23m

Seattle/Tacoma Intl

Tue 21/10

2:05 p.m.-5:51 a.m.

2 stops12h 46m

C$ 318

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 18/10

8:00 a.m.-12:59 p.m.

1 stop7h 59m

Seattle/Tacoma Intl

Wed 22/10

8:40 a.m.-6:52 p.m.

1 stop7h 12m

C$ 318

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 17/9

12:00 p.m.-8:29 p.m.

2 stops11h 29m

Seattle/Tacoma Intl

Wed 24/9

8:40 a.m.-6:52 p.m.

1 stop7h 12m

C$ 321

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 18/10

12:00 p.m.-7:14 p.m.

2 stops10h 14m

Seattle/Tacoma Intl

Tue 21/10

2:05 p.m.-5:51 a.m.

2 stops12h 46m

C$ 321

TorontoSeattle

YTZ - SEA

YTZSEA

Toronto Island

Thu 2/10

12:25 p.m.-7:31 p.m.

1 stop10h 06m

Seattle/Tacoma Intl

Mon 6/10

7:15 a.m.-7:49 p.m.

1 stop9h 34m

C$ 323

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 17/9

12:00 p.m.-8:29 p.m.

2 stops11h 29m

Seattle/Tacoma Intl

Tue 23/9

7:16 a.m.-3:00 p.m.

Nonstop4h 44m

C$ 323

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 28/9

6:45 a.m.-12:35 p.m.

1 stop8h 50m

Seattle/Tacoma Intl

Fri 3/10

1:15 p.m.-12:31 a.m.

1 stop8h 16m

C$ 323

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 17/10

8:00 a.m.-2:16 p.m.

1 stop9h 16m

Seattle/Tacoma Intl

Tue 21/10

5:30 a.m.-7:25 p.m.

2 stops10h 55m

C$ 325

Flights are sorted by cheapest round-trip flights first.

Deals found on 22/8

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, January is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 262). Flying from Region of Ontario to Seattle in December is currently the most expensive (average of C$ 353). 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 24 August 2025.

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 24 August 2025.

The most flights from CAON to SEA are scheduled on a Sunday (6 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (3 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 59m. 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$ 209. Users have also found prices from C$ 210 and C$ 213 on Air Canada and Alaska Airlines, 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 Alaska Airlines (92%), Hawaiian Airlines (92%) or Air Tahiti Nui (90%) 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$ 230. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 304 on average our data indicates C$ 615 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, January is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 262). Flying from Region of Ontario to Seattle in December is currently the most expensive (average of C$ 353). 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
Tukwila
Tacoma
Bothell
Renton
Olympia
Marysville
Lynnwood

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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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Calgary to Spokane flights
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Halifax to Seattle flights
Pierre Elliott Trudeau Intl to Spokane flights
Thunder Bay to Portland flights
Edmonton to Spokane flights
St John to Portland flights
London to Portland flights
Victoria to Portland flights
Québec City to Portland flights
Kamloops to Portland flights
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Windsor to Seattle flights

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 24 August 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 183AverageC$ 413FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 278AverageC$ 507FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 328AverageC$ 515FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 346AverageC$ 560FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
DeltaCheapestC$ 377AverageC$ 504FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Hawaiian AirlinesCheapestC$ 411AverageC$ 464FlexibilityNo 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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