Find flights
Deals
When to book
FAQs

Cheap flights from Ontario to Seattle from C$ 164

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 2/4. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
15 Feb — 22 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 16 January 2026.

Round-trip from

C$ 257

One-way from

C$ 164

Popular in

June

Cheapest in

February

Average price

C$ 553

Good round-trip deal

C$ 305 or less

Good one-way deal

C$ 265 or less
Air Canada
  • Air Canada
  • 23/3-30/3
  • Nonstop
  • 10h 20m total
  • Ontario to Seattle
Search Deals
Alaska Airlines
  • Alaska Airlines
  • 2/4
  • Nonstop
  • 5h 30m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 8% potential increase in price (C$ 62 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (C$ 11 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 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

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 16 January 2026.

Mon 23/37:50 p.m.
YYZ
-
SEA
Nonstop5h 26m
Air Canada
Mon 30/38:00 a.m.
SEA
-
YYZ
Nonstop4h 54m
Air Canada
Deal found 14/1C$ 257
Fri 6/37:45 a.m.
YYZ
-
SEA
1 stop9h 34m
WestJet
Mon 9/33:10 p.m.
SEA
-
YYZ
1 stop12h 03m
WestJet
Deal found 14/1C$ 258
Fri 6/37:45 a.m.
YYZ
-
SEA
1 stop9h 34m
WestJet
Sun 8/33:10 p.m.
SEA
-
YYZ
2 stops11h 48m
WestJet
Deal found 14/1C$ 260
Fri 6/37:45 a.m.
YYZ
-
SEA
1 stop9h 34m
Multiple Airlines
Mon 9/37:55 a.m.
SEA
-
YYZ
Nonstop4h 40m
Multiple Airlines
Deal found 14/1C$ 263
Fri 30/17:50 p.m.
YYZ
-
SEA
Nonstop5h 26m
Air Canada
Mon 2/28:00 p.m.
SEA
-
YYZ
1 stop7h 19m
Air Canada
Deal found 14/1C$ 264
Wed 4/37:45 a.m.
YYZ
-
SEA
1 stop9h 34m
WestJet
Sun 8/33:10 p.m.
SEA
-
YYZ
2 stops11h 48m
WestJet
Deal found 14/1C$ 265
Wed 15/47:45 a.m.
YYZ
-
SEA
1 stop9h 34m
WestJet
Sun 19/43:10 p.m.
SEA
-
YYZ
2 stops11h 48m
WestJet
Deal found 14/1C$ 267
Thu 29/18:00 a.m.
YYZ
-
SEA
1 stop9h 31m
Air Canada
Wed 4/28:10 a.m.
SEA
-
YYZ
Nonstop4h 43m
Air Canada
Deal found 15/1C$ 271
Wed 15/47:45 a.m.
YYZ
-
SEA
1 stop9h 34m
Multiple Airlines
Sun 19/48:05 a.m.
SEA
-
YYZ
Nonstop4h 40m
Multiple Airlines
Deal found 14/1C$ 272
Sat 28/25:55 p.m.
YYZ
-
SEA
1 stop8h 02m
Air Canada
Sat 7/35:50 a.m.
SEA
-
YYZ
1 stop16h 27m
Air Canada
Deal found 14/1C$ 274
Thu 16/47:45 a.m.
YYZ
-
SEA
1 stop9h 34m
Multiple Airlines
Mon 20/48:05 a.m.
SEA
-
YYZ
Nonstop4h 40m
Multiple Airlines
Deal found 14/1C$ 275
Wed 4/37:45 a.m.
YYZ
-
SEA
1 stop9h 34m
Multiple Airlines
Thu 5/37:55 a.m.
SEA
-
YYZ
Nonstop4h 40m
Multiple Airlines
Deal found 14/1C$ 277

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 16 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

Sat 30/5

4:55 p.m.-7:19 p.m.

Nonstop5h 24m

Seattle/Tacoma Intl

Sat 6/6

7:59 a.m.-3:45 p.m.

Nonstop4h 46m

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

Sat 7/3

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

Nonstop4h 40m

C$ 279

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 20/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Sun 1/3

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

Nonstop4h 40m

C$ 297

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 15/4

7:45 a.m.-2:19 p.m.

1 stop9h 34m

Seattle/Tacoma Intl

Sun 19/4

3:10 p.m.-5:28 p.m.

1 stop23h 18m

C$ 302

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 18/2

4:10 p.m.-10:59 p.m.

1 stop9h 49m

Seattle/Tacoma Intl

Mon 23/2

11:59 p.m.-2:01 p.m.

1 stop11h 02m

C$ 306

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 14/2

2:57 p.m.-11:51 p.m.

1 stop11h 54m

Seattle/Tacoma Intl

Mon 23/2

5:20 p.m.-7:30 a.m.

1 stop11h 10m

C$ 306

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 14/4

1:00 p.m.-7:00 p.m.

1 stop9h 00m

Seattle/Tacoma Intl

Sat 18/4

11:59 p.m.-9:54 a.m.

1 stop6h 55m

C$ 306

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 29/1

9:00 a.m.-4:01 p.m.

1 stop10h 01m

Seattle/Tacoma Intl

Sun 1/2

11:45 p.m.-11:48 a.m.

1 stop9h 03m

C$ 306

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Mon 2/3

3:30 p.m.-10:43 p.m.

1 stop10h 13m

Seattle/Tacoma Intl

Sat 7/3

8:00 a.m.-11:46 p.m.

1 stop12h 46m

C$ 306

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Mon 23/3

6:30 a.m.-11:28 p.m.

1 stop19h 58m

Seattle/Tacoma Intl

Mon 30/3

11:59 p.m.-11:49 a.m.

1 stop8h 50m

C$ 306

Flights are sorted by cheapest round-trip flights first.

Deals found on 15/1

Showing 1-10 of 60 results
1
2
3
...
6

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$ 182). Flying from Region of Ontario to Seattle in August is currently the most expensive (average of C$ 310). 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 16 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 16 January 2026.

The most flights from CAON to SEA are scheduled on a Tuesday (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 24m. 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$ 177. Users have also found prices from C$ 198 and C$ 208 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 Montreal Pierre Elliott Trudeau Intl - Seattle/Tacoma Intl or Ottawa - 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$ 211. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 247 on average, our data indicates C$ 439 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$ 182). Flying from Region of Ontario to Seattle in August is currently the most expensive (average of C$ 310). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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
Vancouver Intl to Seattle flights
Calgary to Seattle flights
Edmonton to Seattle flights
Vancouver Intl to Portland flights
Pierre Elliott Trudeau Intl to Seattle flights
Victoria to Seattle flights
Winnipeg to Seattle flights
Ottawa to Seattle flights
Toronto Island to Seattle flights
Pierre Elliott Trudeau Intl to Portland flights
Hamilton to Seattle flights
Kelowna to Seattle flights
Region of Waterloo Intl to Seattle flights
Pearson Intl to Portland flights
Calgary to Portland flights
Ottawa to Portland flights
Québec City to Seattle flights
Saskatoon to Portland flights
Vancouver Intl to Spokane flights
Halifax to Seattle flights
Victoria to Portland flights
London to Seattle flights
Pierre Elliott Trudeau Intl to Spokane flights
Saskatoon to Seattle flights
Pearson Intl to Spokane flights
Edmonton to Portland flights
Calgary to Spokane flights
Regina to Seattle flights
Winnipeg to Portland flights
Toronto Island to Portland flights
Kelowna to Portland flights
Prince George to Seattle flights
Hamilton to Portland flights
Vancouver Intl to Bellingham flights
Thunder Bay to Portland flights
Fort St. John to Portland flights
Edmonton to Spokane flights
Pearson Intl to Pasco flights
Vancouver Intl to Pullman flights
Regina to Portland flights
Kamloops to Portland flights
Nanaimo to Portland flights
Region of Waterloo Intl to Portland flights
London to Portland flights
Québec City to Portland flights
Medicine Hat to Seattle flights
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 16 January 2026.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 128AverageC$ 401FlexibilityNo cancel feeOn-time60%
Search WestJet flights
DeltaCheapestC$ 255AverageC$ 494FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Alaska AirlinesCheapestC$ 276AverageC$ 466FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
United AirlinesCheapestC$ 280AverageC$ 485FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Air CanadaCheapestC$ 323AverageC$ 537FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
Hawaiian AirlinesCheapestC$ 413AverageC$ 466FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.

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.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.