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Cheap flights from Ontario to Seattle from C$ 173

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 19/4. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
7 Feb — 14 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 8 January 2026.

Round-trip from

C$ 256

One-way from

C$ 173

Popular in

June

Cheapest in

February

Average price

C$ 550

Good round-trip deal

C$ 312 or less

Good one-way deal

C$ 250 or less
WestJet
  • WestJet
  • 3/2-10/2
  • 2 total stops
  • 27h 52m total
  • Ontario to Seattle
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WestJet
  • WestJet
  • 19/4
  • 1 total stop
  • 9h 34m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 8% potential increase in price (C$ 61 potential increase over avg. RT price).
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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 January 2026
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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

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 8 January 2026.

Tue 3/27:45 a.m.YYZ - SEA
1 stop9h 34mWestJet
Tue 10/23:10 p.m.SEA - YYZ
1 stop18h 18mWestJet
Deal found 6/1C$ 256
Tue 3/24:45 p.m.YYZ - SEA
Nonstop5h 32mAlaska Airlines
Tue 10/27:55 a.m.SEA - YYZ
Nonstop4h 40mAlaska Airlines
Deal found 6/1C$ 257
Thu 22/14:45 p.m.YYZ - SEA
Nonstop5h 32mMultiple Airlines
Mon 26/13:10 p.m.SEA - YYZ
2 stops11h 48mMultiple Airlines
Deal found 8/1C$ 258
Thu 23/44:55 p.m.YYZ - SEA
Nonstop5h 28mMultiple Airlines
Mon 27/47:05 a.m.SEA - YYZ
1 stop8h 47mMultiple Airlines
Deal found 7/1C$ 261
Fri 10/47:30 a.m.YXU - SEA
1 stop9h 49mWestJet
Mon 27/47:05 a.m.SEA - YXU
1 stop9h 02mWestJet
Deal found 6/1C$ 263
Tue 3/27:45 a.m.YYZ - SEA
1 stop9h 34mMultiple Airlines
Wed 4/27:55 a.m.SEA - YYZ
Nonstop4h 40mMultiple Airlines
Deal found 6/1C$ 263
Tue 3/29:00 a.m.YYZ - SEA
1 stop8h 31mAir Canada
Tue 10/28:10 a.m.SEA - YYZ
Nonstop4h 43mAir Canada
Deal found 7/1C$ 264
Thu 22/14:45 p.m.YYZ - SEA
Nonstop5h 32mMultiple Airlines
Wed 28/18:10 a.m.SEA - YYZ
Nonstop4h 43mMultiple Airlines
Deal found 5/1C$ 267
Mon 16/27:45 a.m.YYZ - SEA
1 stop9h 34mMultiple Airlines
Thu 26/27:55 a.m.SEA - YYZ
Nonstop4h 40mMultiple Airlines
Deal found 6/1C$ 268
Tue 3/26:30 p.m.YYZ - SEA
2 stops22h 49mWestJet
Sun 8/23:10 p.m.SEA - YYZ
2 stops11h 48mWestJet
Deal found 6/1C$ 270
Sun 15/24:45 p.m.YYZ - SEA
Nonstop5h 33mMultiple Airlines
Thu 26/23:10 p.m.SEA - YYZ
2 stops11h 48mMultiple Airlines
Deal found 6/1C$ 272
Fri 27/37:30 a.m.YXU - SEA
1 stop9h 49mWestJet
Fri 8/57:05 a.m.SEA - YXU
1 stop9h 02mWestJet
Deal found 7/1C$ 274

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 8 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

Thu 22/1

4:45 p.m.-7:17 p.m.

Nonstop5h 32m

Seattle/Tacoma Intl

Mon 26/1

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Mon 16/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Wed 25/2

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 6/2

4:45 p.m.-7:17 p.m.

Nonstop5h 32m

Seattle/Tacoma Intl

Tue 10/2

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 27/1

4:45 p.m.-7:17 p.m.

Nonstop5h 32m

Seattle/Tacoma Intl

Thu 29/1

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 8/2

4:45 p.m.-7:17 p.m.

Nonstop5h 32m

Seattle/Tacoma Intl

Wed 18/2

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 17/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Fri 27/2

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 17/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Thu 26/2

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 24/1

4:45 p.m.-7:17 p.m.

Nonstop5h 32m

Seattle/Tacoma Intl

Fri 30/1

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Mon 16/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Thu 26/2

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

Nonstop4h 40m

C$ 257

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 15/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Fri 27/2

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

Nonstop4h 40m

C$ 257

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/1

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$ 181). Flying from Region of Ontario to Seattle in June is currently the most expensive (average of C$ 344). 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 8 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 8 January 2026.

The most flights from CAON to SEA are scheduled on a Wednesday (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 32m. 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$ 176. Users have also found prices from C$ 197 and C$ 207 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 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 (68%), Alaska Airlines (63%) or Hawaiian Airlines (63%) 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$ 169. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 235 on average, our data indicates C$ 411 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$ 181). Flying from Region of Ontario to Seattle in June is currently the most expensive (average of C$ 344). 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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Victoria to Portland flights
Vancouver Intl to Spokane flights
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Halifax to Seattle flights
Regina to Seattle flights
Winnipeg to Portland flights
Hamilton to Portland flights
Saskatoon to Seattle flights
Edmonton to Spokane flights
Region of Waterloo Intl to Portland flights
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Fort St. John to Portland flights
Pearson Intl to Spokane flights
Vancouver Intl to Bellingham flights
Kelowna to Portland flights
Saskatoon to Portland flights
Thunder Bay to Portland flights
Pierre Elliott Trudeau Intl to Pasco flights
Nanaimo to Portland flights
Kamloops to Portland flights
London to Portland flights
Québec City to Portland flights
Regina to Portland flights
Windsor to Seattle flights
Medicine Hat to Seattle flights
Campbell River 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 8 January 2026.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 183AverageC$ 400FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 278AverageC$ 492FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 278AverageC$ 465FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 337AverageC$ 537FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
DeltaCheapestC$ 343AverageC$ 492FlexibilityNo 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?

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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