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Cheap flights from Ontario to Seattle from C$ 214

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 6/5. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
25 May — 1 Jun1
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 25 April 2026.

Thu 16/712:00 p.m.
YYZ
-
SEA
2 stops9h 45m
WestJet
Sat 1/87:35 p.m.
SEA
-
YYZ
1 stop8h 20m
WestJet
Deal found 25/4C$ 309
Fri 10/73:50 p.m.
YYZ
-
SEA
1 stop8h 10m
WestJet
Sat 18/77:00 a.m.
SEA
-
YYZ
1 stop8h 55m
WestJet
Deal found 23/4C$ 311
Tue 25/81:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Thu 27/87:35 p.m.
SEA
-
YYZ
1 stop7h 10m
WestJet
Deal found 23/4C$ 312
Thu 20/812:00 p.m.
YYZ
-
SEA
2 stops12h 00m
WestJet
Fri 28/810:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 21/4C$ 313
Sat 18/71:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Sat 1/810:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 25/4C$ 315
Thu 7/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Wed 13/510:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 21/4C$ 316
Thu 7/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Sat 16/510:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 23/4C$ 318
Mon 1/612:00 p.m.
YYZ
-
SEA
2 stops9h 45m
WestJet
Wed 10/610:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 23/4C$ 319
Fri 7/812:00 p.m.
YYZ
-
SEA
2 stops9h 45m
WestJet
Sat 22/810:30 a.m.
SEA
-
YYZ
1 stop9h 15m
WestJet
Deal found 25/4C$ 320
Tue 19/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Tue 26/510:30 a.m.
SEA
-
YYZ
1 stop7h 45m
WestJet
Deal found 21/4C$ 322
Thu 6/81:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Tue 25/87:00 a.m.
SEA
-
YYZ
1 stop8h 55m
WestJet
Deal found 25/4C$ 323
Mon 18/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Tue 28/710:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 22/4C$ 324

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 25 April 2026.

Round-trip from

C$ 309

One-way from

C$ 214

Popular in

June

Cheapest in

February

Average price

C$ 553

Good round-trip deal

C$ 502 or less

Good one-way deal

C$ 265 or less
WestJet
  • WestJet
  • 16/7-1/8
  • 3 total stops
  • 18h 05m total
  • Ontario to Seattle
Search Deals
Alaska Airlines
  • Alaska Airlines
  • 6/5
  • Nonstop
  • 5h 28m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 7% potential increase in price (C$ 49 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 15 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 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 25 April 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

Sat 20/6

8:40 p.m.-6:45 p.m.

1 stop25h 05m

Seattle/Tacoma Intl

Wed 24/6

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

1 stop21h 15m

C$ 368

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Fri 19/6

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

1 stop16h 00m

Seattle/Tacoma Intl

Wed 24/6

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

1 stop9h 50m

C$ 374

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Wed 10/6

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

1 stop16h 00m

Seattle/Tacoma Intl

Fri 19/6

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

1 stop21h 15m

C$ 375

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 4/6

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

1 stop16h 00m

Seattle/Tacoma Intl

Thu 11/6

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

1 stop21h 15m

C$ 383

MontrealSeattle

YUL - SEA

YULSEA

Montreal Pierre Elliott Trudeau Intl

Sat 16/5

7:15 a.m.-9:40 a.m.

1 stop29h 25m

Seattle/Tacoma Intl

Sat 22/8

7:35 p.m.-7:05 a.m.

1 stop8h 30m

C$ 389

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Wed 17/6

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

1 stop16h 00m

Seattle/Tacoma Intl

Tue 23/6

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

1 stop9h 50m

C$ 393

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 22/5

4:18 p.m.-8:00 a.m.

1 stop18h 42m

Seattle/Tacoma Intl

Mon 25/5

10:40 p.m.-11:49 a.m.

1 stop10h 09m

C$ 394

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Sat 20/6

6:10 p.m.-6:45 p.m.

1 stop27h 35m

Seattle/Tacoma Intl

Wed 24/6

7:35 p.m.-5:15 p.m.

1 stop18h 40m

C$ 394

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Fri 8/5

6:10 p.m.-9:40 a.m.

1 stop18h 30m

Seattle/Tacoma Intl

Mon 11/5

7:35 p.m.-5:15 p.m.

1 stop18h 40m

C$ 401

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Sun 24/5

6:10 p.m.-9:40 a.m.

1 stop18h 30m

Seattle/Tacoma Intl

Sun 14/6

7:35 p.m.-5:15 p.m.

1 stop18h 40m

C$ 402

Flights are sorted by cheapest round-trip flights first.

Deals found on 24/4

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

How far ahead should I book a flight from Region of Ontario to Seattle?

Booking 85 days in advance of your planned departure date is, on average, the best time to get cheap flights from Region of Ontario to Seattle. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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$ 86). Flying from Region of Ontario to Seattle in July is currently the most expensive (average of C$ 1,092). 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 25 April 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 11h 10m. 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$ 120. Users have also found prices from C$ 162 and C$ 168 on United Airlines 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 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 (93%), Alaska Airlines (70%) or Hawaiian Airlines (70%) 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$ 228. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 298 on average, our data indicates C$ 484 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$ 86). Flying from Region of Ontario to Seattle in July is currently the most expensive (average of C$ 1,092). 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
Kent
Tacoma
Bothell
Cashmere
Olympia
Renton
Marysville
Lynnwood
Kirkland
Tukwila

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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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London to Seattle flights
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Winnipeg to Portland flights
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St John to Portland flights
Pearson Intl to Pasco flights
Vancouver Intl to Pullman flights
Kelowna to Portland flights
Kamloops to Portland flights
London to Portland flights
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Sault Ste Marie to Seattle flights
Fort St. John 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 25 April 2026.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 247AverageC$ 417FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 249AverageC$ 583FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 269AverageC$ 448FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
DeltaCheapestC$ 276AverageC$ 486FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air CanadaCheapestC$ 294AverageC$ 532FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
Hawaiian AirlinesCheapestC$ 371AverageC$ 652FlexibilityNo 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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