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Cheap flights from Ontario to Seattle from C$ 161

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 5/6. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
17 Mar — 24 Mar1
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 15 February 2026.

Thu 4/61:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Mon 8/67:35 p.m.
SEA
-
YYZ
1 stop7h 10m
WestJet
Deal found 15/2C$ 253
Fri 22/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Mon 25/57:35 p.m.
SEA
-
YYZ
1 stop8h 20m
WestJet
Deal found 13/2C$ 255
Fri 8/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Fri 15/510:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 12/2C$ 257
Thu 21/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Thu 4/67:35 p.m.
SEA
-
YYZ
1 stop7h 10m
WestJet
Deal found 11/2C$ 261
Fri 22/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Fri 5/67:35 p.m.
SEA
-
YYZ
1 stop7h 10m
WestJet
Deal found 11/2C$ 263
Mon 11/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Wed 13/57:35 p.m.
SEA
-
YYZ
1 stop7h 10m
WestJet
Deal found 14/2C$ 264
Tue 12/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Sat 16/57:35 p.m.
SEA
-
YYZ
1 stop7h 10m
WestJet
Deal found 14/2C$ 265
Thu 21/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Fri 5/610:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 11/2C$ 268
Fri 22/51:30 p.m.
YYZ
-
SEA
1 stop8h 15m
WestJet
Tue 2/67:35 p.m.
SEA
-
YYZ
1 stop7h 10m
WestJet
Deal found 11/2C$ 271
Wed 29/410:00 a.m.
YYZ
-
SEA
1 stop11h 45m
WestJet
Tue 5/510:30 a.m.
SEA
-
YYZ
2 stops10h 29m
WestJet
Deal found 14/2C$ 274
Fri 24/47:30 a.m.
YXU
-
SEA
1 stop9h 49m
WestJet
Wed 29/47:35 p.m.
SEA
-
YXU
1 stop6h 45m
WestJet
Deal found 13/2C$ 286
Tue 26/51:20 p.m.
YOW
-
SEA
1 stop8h 25m
WestJet
Fri 5/67:35 p.m.
SEA
-
YOW
1 stop7h 05m
WestJet
Deal found 11/2C$ 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 15 February 2026.

Round-trip from

C$ 253

One-way from

C$ 161

Popular in

June

Cheapest in

February

Average price

C$ 354

Good round-trip deal

C$ 389 or less

Good one-way deal

C$ 274 or less
WestJet
  • WestJet
  • 4/6-8/6
  • 2 total stops
  • 15h 25m total
  • Ontario to Seattle
Search Deals
WestJet
  • WestJet
  • 5/6
  • 2 total stops
  • 9h 45m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 6% potential increase in price (C$ 41 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (C$ 12 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 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 15 February 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

Wed 11/3

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

Nonstop5h 33m

Seattle/Tacoma Intl

Sun 15/3

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

2 stops11h 48m

C$ 278

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 28/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Wed 4/3

7:55 a.m.-3:35 p.m.

Nonstop4h 40m

C$ 280

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 28/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Sat 7/3

7:55 a.m.-3:35 p.m.

Nonstop4h 40m

C$ 280

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 4/3

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

Nonstop5h 33m

Seattle/Tacoma Intl

Wed 11/3

7:55 a.m.-3:35 p.m.

Nonstop4h 40m

C$ 282

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 24/4

7:30 a.m.-2:19 p.m.

1 stop9h 49m

Seattle/Tacoma Intl

Wed 29/4

7:35 p.m.-5:20 a.m.

1 stop6h 45m

C$ 286

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 11/3

6:30 p.m.-2:19 p.m.

2 stops22h 49m

Seattle/Tacoma Intl

Sun 15/3

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

2 stops11h 48m

C$ 302

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 22/4

10:45 a.m.-8:57 p.m.

2 stops13h 12m

Seattle/Tacoma Intl

Wed 29/4

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

2 stops11h 14m

C$ 325

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 28/2

8:45 a.m.-6:03 p.m.

2 stops12h 18m

Seattle/Tacoma Intl

Wed 4/3

7:10 p.m.-9:36 a.m.

2 stops11h 26m

C$ 325

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 13/5

6:30 a.m.-12:25 p.m.

1 stop8h 55m

Seattle/Tacoma Intl

Wed 13/5

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

1 stop10h 00m

C$ 325

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 13/5

7:00 a.m.-10:42 p.m.

1 stop18h 42m

Seattle/Tacoma Intl

Sat 16/5

11:14 p.m.-7:02 p.m.

1 stop16h 48m

C$ 325

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/2

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$ 178). Flying from Region of Ontario to Seattle in July is currently the most expensive (average of C$ 321). 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 15 February 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 15 February 2026.

The most flights from CAON to SEA are scheduled on a Thursday (6 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (2 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 5h 33m. 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 Delta. According to our data, you can fly for as low as C$ 151. Users have also found prices from C$ 167 and C$ 173 on Alaska Airlines and WestJet, 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 Montreal Pierre Elliott Trudeau Intl - 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 (48%), Alaska Airlines (48%) or Hawaiian Airlines (48%) 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$ 161. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 260 on average, our data indicates C$ 840 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$ 178). Flying from Region of Ontario to Seattle in July is currently the most expensive (average of C$ 321). 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

Browse thousands of different options on Cheapflights for your next trip

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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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Vancouver Intl to Seattle flights
Calgary to Seattle flights
Edmonton to Seattle flights
Hamilton to Seattle flights
Pierre Elliott Trudeau Intl to Seattle flights
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Toronto Island to Seattle flights
Pierre Elliott Trudeau Intl to Portland flights
Kelowna to Seattle flights
Ottawa to Seattle flights
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Region of Waterloo Intl to Seattle flights
Pearson Intl to Portland flights
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Halifax to Seattle flights
Ottawa to Portland flights
Pierre Elliott Trudeau Intl to Spokane flights
Toronto Island to Portland flights
Prince George to Seattle flights
Victoria to Portland flights
Pearson Intl to Spokane flights
Edmonton to Portland flights
Saskatoon to Portland flights
Regina to Seattle flights
Winnipeg to Portland flights
Calgary to Spokane flights
Regina to Portland flights
London to Seattle flights
Nanaimo to Portland flights
Québec City to Portland flights
Fort St. John to Portland flights
Hamilton to Portland flights
Kelowna to Portland flights
Windsor to Seattle flights
Kamloops to Portland flights
Vancouver Intl to Bellingham flights
London to Portland flights
Vancouver Intl to Pullman flights
Region of Waterloo Intl to Portland flights
Kelowna to Bellingham flights
Sault Ste Marie to Seattle flights
Pearson Intl to Pasco flights
Pierre Elliott Trudeau Intl to Pasco flights
St John to Portland 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 15 February 2026.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 126AverageC$ 386FlexibilityNo cancel feeOn-time60%
Search WestJet flights
DeltaCheapestC$ 250AverageC$ 483FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
United AirlinesCheapestC$ 261AverageC$ 475FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 270AverageC$ 464FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 322AverageC$ 535FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
Hawaiian AirlinesCheapestC$ 405AverageC$ 457FlexibilityNo 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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