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Cheap flights from Ontario to Seattle from C$ 202

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 9/3. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
15 Jan — 22 Jan1
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 16 December 2025.

Fri 26/121:30 p.m.YYZ - SEA
1 stop10h 16mMultiple Airlines
Wed 7/17:55 a.m.SEA - YYZ
Nonstop4h 40mMultiple Airlines
Deal found 14/12C$ 610
Tue 30/122:50 p.m.YYZ - SEA
1 stop11h 22mUnited Airlines
Tue 6/13:30 p.m.SEA - YYZ
2 stops15h 16mUnited Airlines
Deal found 14/12C$ 630
Sun 28/1210:15 p.m.YYZ - SEA
1 stop12h 05mMultiple Airlines
Sat 10/17:55 a.m.SEA - YYZ
Nonstop4h 40mMultiple Airlines
Deal found 16/12C$ 647
Sun 28/1210:15 p.m.YYZ - SEA
1 stop12h 05mWestJet
Sat 10/111:55 a.m.SEA - YYZ
2 stops8h 44mWestJet
Deal found 16/12C$ 656
Fri 26/121:30 p.m.YYZ - SEA
1 stop10h 16mWestJet
Wed 7/13:10 p.m.SEA - YYZ
1 stop29h 01mWestJet
Deal found 14/12C$ 685
Fri 26/1210:00 a.m.YYZ - SEA
1 stop13h 57mUnited Airlines
Wed 7/111:45 p.m.SEA - YYZ
1 stop9h 03mUnited Airlines
Deal found 15/12C$ 687
Sun 28/128:30 a.m.YYZ - SEA
1 stop17h 42mUnited Airlines
Thu 15/18:10 a.m.SEA - YYZ
Nonstop4h 43mUnited Airlines
Deal found 16/12C$ 696
Mon 22/124:15 p.m.YUL - SEA
2 stops31h 31mWestJet
Thu 8/13:10 p.m.SEA - YUL
1 stop12h 55mWestJet
Deal found 15/12C$ 794
Mon 22/129:00 a.m.YUL - SEA
1 stop8h 31mAir Canada
Mon 29/125:50 a.m.SEA - YUL
2 stops10h 24mAir Canada
Deal found 15/12C$ 859
Mon 22/123:59 p.m.YUL - SEA
2 stops22h 00mAmerican Airlines
Wed 7/110:50 a.m.SEA - YUL
2 stops25h 18mAmerican Airlines
Deal found 15/12C$ 861
Thu 25/129:15 a.m.YUL - SEA
2 stops15h 02mUnited Airlines
Tue 6/15:10 p.m.SEA - YUL
2 stops14h 10mUnited Airlines
Deal found 15/12C$ 866
Tue 23/123:10 p.m.YUL - SEA
1 stop10h 06mAir Canada
Tue 30/125:50 a.m.SEA - YUL
1 stop8h 10mAir Canada
Deal found 15/12C$ 867

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 16 December 2025.

Round-trip from

C$ 272

One-way from

C$ 202

Popular in

December

Cheapest in

February

Average price

C$ 618

Good round-trip deal

C$ 324 or less

Good one-way deal

C$ 252 or less
Alaska Airlines
  • Alaska Airlines
  • 7/3-10/3
  • Nonstop
  • 10h 13m total
  • Ontario to Seattle
Search Deals
WestJet
  • WestJet
  • 9/3
  • 1 total stop
  • 23h 09m total
  • Ontario to Seattle
Search Deals
High demand for flights, 0% potential price rise
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 19 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
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 16 December 2025.
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

Tue 14/4

4:45 p.m.-7:05 p.m.

Nonstop5h 20m

Seattle/Tacoma Intl

Sat 18/4

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

Nonstop4h 40m

C$ 274

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 7/3

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

Nonstop5h 33m

Seattle/Tacoma Intl

Tue 10/3

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

Nonstop4h 40m

C$ 274

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 20/1

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

Nonstop5h 32m

Seattle/Tacoma Intl

Thu 5/2

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

Nonstop4h 40m

C$ 283

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 24/1

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

Nonstop5h 32m

Seattle/Tacoma Intl

Sat 31/1

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

Nonstop4h 40m

C$ 290

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 25/1

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

Nonstop5h 32m

Seattle/Tacoma Intl

Sun 8/2

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

Nonstop4h 40m

C$ 292

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 22/1

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

Nonstop5h 32m

Seattle/Tacoma Intl

Sun 25/1

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

Nonstop4h 40m

C$ 292

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 5/5

9:00 a.m.-8:28 p.m.

2 stops14h 28m

Seattle/Tacoma Intl

Sun 24/5

7:05 a.m.-9:00 p.m.

2 stops10h 55m

C$ 293

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 13/2

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

Nonstop5h 33m

Seattle/Tacoma Intl

Wed 18/2

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

Nonstop4h 40m

C$ 301

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 23/1

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$ 312

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 15/1

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

Nonstop5h 32m

Seattle/Tacoma Intl

Sun 18/1

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

Nonstop4h 40m

C$ 312

Flights are sorted by cheapest round-trip flights first.

Deals found on 16/12

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$ 183). Flying from Region of Ontario to Seattle in June is currently the most expensive (average of C$ 343). 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 December 2025.

Unlike in the afternoon, when flights are generally more expensive, you can save up to 19% on flights from Region of Ontario to Seattle by exploring options for tickets in the evening.

What is the cheapest day to fly from Region of Ontario to Seattle?

Use this chart to determine the cheapest time to fly round-trip from Ontario to Seattle. Price data was last updated on 16 December 2024.

Travelers seeking maximum savings on their Region of Ontario to Seattle flight should consider departing on Thursday evenings when fares are most often at their lowest. Saturday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

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 December 2025.

The most flights from CAON to SEA are scheduled on a Tuesday (7 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (2 on average).

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 20m. 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$ 183. Users have also found prices from C$ 193 and C$ 206 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 Hawaiian Airlines (90%), Air Tahiti Nui (90%) or Qatar Airways (77%) 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$ 154. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 268 on average, our data indicates C$ 438 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$ 183). Flying from Region of Ontario to Seattle in June is currently the most expensive (average of C$ 343). 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
Tukwila
Bothell
Cashmere
Olympia
Renton
Marysville
Lynnwood

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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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Hamilton to Portland flights
Vancouver Intl to Bellingham flights
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Pearson Intl to Pasco flights
Thunder Bay to Portland flights
Nanaimo to Portland flights
London to Portland flights
Pierre Elliott Trudeau Intl to Pasco flights
Fort St. John to Portland flights
St John to Portland flights
Kelowna to Portland flights
Kamloops to Portland 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 16 December 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 182AverageC$ 403FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 277AverageC$ 487FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 283AverageC$ 471FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 336AverageC$ 538FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
DeltaCheapestC$ 341AverageC$ 492FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Hawaiian AirlinesCheapestC$ 409AverageC$ 462FlexibilityNo 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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