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Cheap flights from Ontario to Seattle from C$ 205

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 11/1. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
16 Nov — 23 Nov1
1 adult
1 adult, Economy

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 17 October 2025.

Thu 20/117:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Mon 24/113:10 p.m.SEA - YYZ
2 stops11h 48mWestJet
Deal found 16/10C$ 302
Mon 8/127:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Thu 11/123:10 p.m.SEA - YYZ
2 stops11h 48mWestJet
Deal found 16/10C$ 306
Thu 13/117:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Thu 20/113:10 p.m.SEA - YYZ
2 stops11h 48mWestJet
Deal found 16/10C$ 313
Tue 18/117:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Fri 21/1111:55 a.m.SEA - YYZ
1 stop16h 03mWestJet
Deal found 15/10C$ 316
Fri 14/117:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Fri 21/1111:55 a.m.SEA - YYZ
1 stop16h 03mWestJet
Deal found 16/10C$ 323
Thu 13/117:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Fri 21/1111:55 a.m.SEA - YYZ
1 stop16h 03mWestJet
Deal found 15/10C$ 327
Thu 20/117:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Sat 22/1111:55 a.m.SEA - YYZ
2 stops8h 44mWestJet
Deal found 15/10C$ 330
Thu 13/117:45 a.m.YYZ - SEA
1 stop9h 35mWestJet
Sat 22/1111:55 a.m.SEA - YYZ
2 stops8h 44mWestJet
Deal found 15/10C$ 331
Thu 13/116:10 p.m.YHM - SEA
1 stop23h 10mWestJet
Sun 23/113:10 p.m.SEA - YHM
1 stop23h 07mWestJet
Deal found 14/10C$ 388
Mon 1/127:30 p.m.YUL - SEA
1 stop21h 50mWestJet
Sun 7/123:10 p.m.SEA - YUL
1 stop21h 02mWestJet
Deal found 14/10C$ 400
Mon 15/126:10 p.m.YHM - SEA
1 stop23h 10mWestJet
Tue 6/13:10 p.m.SEA - YHM
1 stop23h 07mWestJet
Deal found 13/10C$ 409
Wed 22/106:00 a.m.YHM - SEA
1 stop9h 59mWestJet
Thu 23/101:50 p.m.SEA - YHM
1 stop7h 50mWestJet
Deal found 14/10C$ 431

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 17 October 2025.

Round-trip from

C$ 302

One-way from

C$ 205

Popular in

December

Cheapest in

February

Average price

C$ 462

Good round-trip deal

C$ 362 or less

Good one-way deal

C$ 316 or less
WestJet
  • WestJet
  • 20/11-24/11
  • 3 total stops
  • 21h 23m total
  • Ontario to Seattle
Search Deals
WestJet
  • WestJet
  • 14/11
  • 2 total stops
  • 11h 40m total
  • Ontario to Seattle
Search Deals
High demand for flights, 3% potential price rise
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 14 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 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 17 October 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

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Thu 5/3

5:57 p.m.-11:52 p.m.

1 stop8h 55m

Seattle/Tacoma Intl

Tue 10/3

8:00 p.m.-6:43 a.m.

1 stop7h 43m

C$ 331

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Tue 27/1

6:20 a.m.-11:32 a.m.

1 stop8h 12m

Seattle/Tacoma Intl

Sun 1/2

8:00 p.m.-6:43 a.m.

1 stop7h 43m

C$ 331

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Wed 28/1

6:20 a.m.-10:43 p.m.

1 stop19h 23m

Seattle/Tacoma Intl

Mon 2/2

8:00 p.m.-6:43 a.m.

1 stop7h 43m

C$ 331

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Tue 14/4

5:50 p.m.-10:08 p.m.

1 stop7h 18m

Seattle/Tacoma Intl

Wed 15/4

8:00 p.m.-6:43 a.m.

1 stop7h 43m

C$ 340

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Tue 24/2

5:50 a.m.-2:19 p.m.

1 stop11h 29m

Seattle/Tacoma Intl

Thu 26/2

3:10 p.m.-1:21 p.m.

1 stop19h 11m

C$ 344

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Wed 28/1

2:15 p.m.-12:51 a.m.

2 stops13h 36m

Seattle/Tacoma Intl

Mon 2/2

9:25 a.m.-11:54 p.m.

2 stops11h 29m

C$ 347

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Tue 14/4

6:52 a.m.-3:05 p.m.

2 stops11h 13m

Seattle/Tacoma Intl

Wed 15/4

5:00 p.m.-1:45 p.m.

2 stops17h 45m

C$ 347

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Thu 5/3

5:57 p.m.-11:52 p.m.

1 stop8h 55m

Seattle/Tacoma Intl

Tue 10/3

12:46 p.m.-10:26 a.m.

2 stops18h 40m

C$ 348

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sat 8/11

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

Nonstop5h 20m

Seattle/Tacoma Intl

Sat 15/11

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

Nonstop4h 40m

C$ 358

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 12/11

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

Nonstop5h 20m

Seattle/Tacoma Intl

Wed 19/11

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

Nonstop4h 40m

C$ 361

Flights are sorted by cheapest round-trip flights first.

Deals found on 15/10

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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, May is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 129). Flying from Region of Ontario to Seattle in June is currently the most expensive (average of C$ 350). 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 17 October 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 17 October 2025.

The most flights from CAON to SEA are scheduled on a Tuesday (6 on average). You will have fewer flight options on Friday, 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 Delta. According to our data, you can fly for as low as C$ 226. Users have also found prices from C$ 226 and C$ 232 on Alaska Airlines and United 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 Hamilton - 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 (98%), Alaska Airlines (95%) or Hawaiian Airlines (95%) 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$ 247. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 330 on average, our data indicates C$ 424 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, May is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 129). Flying from Region of Ontario to Seattle in June is currently the most expensive (average of C$ 350). 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
Tukwila
Tacoma
Mukilteo
Bothell
Cashmere
Renton
Olympia
Marysville
Lynnwood

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
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Kelowna to Seattle flights
Pearson Intl to Portland flights
Ottawa to Seattle flights
Pierre Elliott Trudeau Intl to Portland flights
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London to Seattle flights
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Prince George to Seattle flights
Calgary to Portland flights
Regina to Portland flights
Toronto Island to Portland flights
Saskatoon to Portland flights
Pearson Intl to Spokane flights
Pierre Elliott Trudeau Intl to Spokane flights
Edmonton to Spokane flights
Calgary to Spokane flights
Québec City to Portland flights
Ottawa to Portland flights
Region of Waterloo Intl to Portland flights
Vancouver Intl to Bellingham flights
Hamilton to Portland flights
Victoria to Portland flights
Pierre Elliott Trudeau Intl to Pasco flights
Kamloops to Portland flights
London to Portland flights
Thunder Bay to Portland flights
St John to Portland 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 17 October 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 186AverageC$ 415FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 282AverageC$ 496FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 300AverageC$ 516FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 346AverageC$ 557FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
DeltaCheapestC$ 379AverageC$ 501FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Hawaiian AirlinesCheapestC$ 418AverageC$ 471FlexibilityNo 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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