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Cheap flights from Ontario to Seattle from C$ 207

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 23/4. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
27 Apr — 4 May1
1 adult
1 adult, Economy, 0 bags

Cheap 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 28 March 2026.

Wed 22/44:55 p.m.
YYZ
-
SEA
Nonstop5h 28m
Alaska Airlines
Wed 29/47:55 a.m.
SEA
-
YYZ
Nonstop4h 50m
Alaska Airlines
Deal found 25/3C$ 315
Tue 28/46:10 a.m.
YYZ
-
SEA
2 stops30h 30m
WestJet
Sat 2/510:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 27/3C$ 316
Thu 23/47:30 p.m.
YYZ
-
SEA
Nonstop5h 23m
Air Canada
Wed 29/48:00 a.m.
SEA
-
YYZ
Nonstop4h 54m
Air Canada
Deal found 26/3C$ 319
Fri 19/66:10 p.m.
YHM
-
SEA
1 stop29h 50m
WestJet
Mon 22/67:00 a.m.
SEA
-
YHM
1 stop7h 15m
WestJet
Deal found 27/3C$ 320
Thu 23/44:55 p.m.
YYZ
-
SEA
Nonstop5h 28m
Alaska Airlines
Sat 25/47:55 a.m.
SEA
-
YYZ
Nonstop4h 50m
Alaska Airlines
Deal found 25/3C$ 326
Sat 30/512:00 p.m.
YYZ
-
SEA
1 stop9h 45m
WestJet
Sat 6/610:30 a.m.
SEA
-
YYZ
2 stops15h 40m
WestJet
Deal found 27/3C$ 330
Fri 1/512:30 a.m.
YYZ
-
SEA
2 stops12h 35m
Air Canada
Sat 9/57:20 p.m.
SEA
-
YYZ
2 stops9h 50m
Air Canada
Deal found 24/3C$ 334
Sat 2/54:55 p.m.
YYZ
-
SEA
Nonstop5h 28m
Multiple Airlines
Sat 9/58:00 a.m.
SEA
-
YYZ
Nonstop4h 50m
Multiple Airlines
Deal found 24/3C$ 336
Thu 23/44:55 p.m.
YYZ
-
SEA
Nonstop5h 28m
Alaska Airlines
Sun 26/47:55 a.m.
SEA
-
YYZ
Nonstop4h 50m
Alaska Airlines
Deal found 25/3C$ 337
Fri 19/68:40 p.m.
YKF
-
SEA
1 stop27h 20m
WestJet
Mon 22/67:00 a.m.
SEA
-
YKF
1 stop9h 50m
WestJet
Deal found 27/3C$ 345
Tue 28/47:30 p.m.
YYZ
-
SEA
Nonstop5h 23m
Air Canada
Tue 5/57:20 p.m.
SEA
-
YYZ
1 stop10h 43m
Air Canada
Deal found 26/3C$ 348
Fri 1/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Tue 5/57:35 p.m.
SEA
-
YYZ
1 stop8h 20m
WestJet
Deal found 27/3C$ 349

Find flight deals from Ontario to Seattle

Keep the following information in mind while searching for Ontario to Seattle flight deals. Data was last updated 28 March 2026.

Round-trip from

C$ 315

One-way from

C$ 207

Popular in

June

Cheapest in

February

Average price

C$ 462

Good round-trip deal

C$ 445 or less

Good one-way deal

C$ 284 or less
Alaska Airlines
  • Alaska Airlines
  • 22/4-29/4
  • Nonstop
  • 10h 18m total
  • Ontario to Seattle
Search Deals
Alaska Airlines
  • Alaska Airlines
  • 23/4
  • Nonstop
  • 5h 28m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 4% potential increase in price (C$ 33 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (C$ 13 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 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.
Search Deals

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 28 March 2026.
Use the filters below to find and compare flights from Ontario to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Fri 19/6

8:40 p.m.-9:00 p.m.

1 stop27h 20m

Seattle/Tacoma Intl

Mon 22/6

7:00 a.m.-7:50 p.m.

1 stop9h 50m

C$ 345

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 10/5

9:49 a.m.-6:49 p.m.

1 stop12h 00m

Seattle/Tacoma Intl

Wed 13/5

9:35 p.m.-12:19 p.m.

1 stop11h 44m

C$ 377

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 29/4

12:22 p.m.-8:42 p.m.

1 stop11h 20m

Seattle/Tacoma Intl

Fri 1/5

11:59 p.m.-11:32 a.m.

1 stop8h 33m

C$ 383

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 21/4

11:30 a.m.-6:54 p.m.

1 stop10h 24m

Seattle/Tacoma Intl

Tue 28/4

6:00 a.m.-6:31 p.m.

1 stop9h 31m

C$ 384

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 10/5

6:12 p.m.-10:48 p.m.

1 stop7h 36m

Seattle/Tacoma Intl

Sun 17/5

5:30 a.m.-3:14 p.m.

1 stop6h 44m

C$ 384

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 23/4

5:16 p.m.-11:27 p.m.

1 stop9h 11m

Seattle/Tacoma Intl

Wed 29/4

7:05 p.m.-9:19 a.m.

2 stops11h 14m

C$ 412

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 4/6

6:12 p.m.-10:46 p.m.

1 stop7h 34m

Seattle/Tacoma Intl

Mon 8/6

11:10 p.m.-8:55 a.m.

1 stop6h 45m

C$ 423

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Mon 27/4

7:22 p.m.-11:54 p.m.

1 stop7h 32m

Seattle/Tacoma Intl

Fri 1/5

11:59 p.m.-11:32 a.m.

1 stop8h 33m

C$ 424

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 7/5

4:55 p.m.-7:23 p.m.

Nonstop5h 28m

Seattle/Tacoma Intl

Sat 16/5

6:00 a.m.-5:19 p.m.

1 stop8h 19m

C$ 438

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Wed 29/4

8:40 p.m.-9:40 a.m.

1 stop16h 00m

Seattle/Tacoma Intl

Tue 5/5

7:35 p.m.-7:50 p.m.

1 stop21h 15m

C$ 438

Flights are sorted by cheapest round-trip flights first.

Deals found on 27/3

Showing 1-10 of 60 resultsSorted by cheapest first
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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$ 182). Flying from Region of Ontario to Seattle in July is currently the most expensive (average of C$ 327). 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 28 March 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.

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 9h 11m. 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$ 122. Users have also found prices from C$ 153 and C$ 164 on Delta and United 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 Hamilton - Seattle/Tacoma Intl or Toronto Island - 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 Air Tahiti Nui (80%), Qatar Airways (79%) or Alaska Airlines (75%) 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$ 214. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 326 on average, our data indicates C$ 471 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$ 182). Flying from Region of Ontario to Seattle in July is currently the most expensive (average of C$ 327). 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
SeaTac
Leavenworth
Mukilteo
Tacoma
Kent
Bothell
Cashmere
Tukwila
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.
Pearson Intl to Seattle flights
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Ottawa to Portland flights
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Region of Waterloo Intl to Portland flights
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Edmonton to Portland flights
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Pearson Intl to Spokane flights
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Victoria to Portland flights
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Prince George to Seattle flights
Regina to Portland flights
Pierre Elliott Trudeau Intl to Spokane flights
Nanaimo to Portland flights
London to Seattle flights
Vancouver Intl to Pullman flights
Sault Ste Marie to Seattle flights
Saskatoon to Portland flights
Campbell River to Seattle flights
Kelowna to Portland flights
Kamloops to Portland flights
Pierre Elliott Trudeau Intl to Pasco flights
St John to Portland flights
London to Portland flights
Pearson Intl to Pasco flights
Edmonton to Spokane 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 28 March 2026.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 128AverageC$ 391FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 252AverageC$ 470FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 273AverageC$ 455FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
DeltaCheapestC$ 280AverageC$ 491FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air CanadaCheapestC$ 308AverageC$ 551FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
Hawaiian AirlinesCheapestC$ 412AverageC$ 512FlexibilityNo 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?

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Seattle from Ontario today with Cheapflights!

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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