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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 20/10. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
15 Oct — 22 Oct1
1 adult
1 adult, Economy

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 15 September 2025.

Round-trip from

C$ 282

One-way from

C$ 173

Popular in

December

Cheapest in

February

Average price

C$ 547

Good round-trip deal

C$ 494 or less

Good one-way deal

C$ 431 or less
WestJet
  • WestJet
  • 21/10-24/10
  • 2 total stops
  • 17h 49m total
  • Ontario to Seattle
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WestJet
  • WestJet
  • 20/10
  • 1 total stop
  • 9h 59m total
  • Ontario to Seattle
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High demand for flights, 7% potential price rise
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Cheapest flight prices on average. 1% potential price decrease (C$ 10 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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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

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 September 2025.

Tue 21/106:00 a.m.YHM - SEA
1 stop9h 59mWestJet
Fri 24/101:50 p.m.SEA - YHM
1 stop7h 50mWestJet
Deal found 13/9C$ 282
Mon 20/106:00 a.m.YHM - SEA
1 stop9h 59mWestJet
Fri 24/101:50 p.m.SEA - YHM
1 stop7h 50mWestJet
Deal found 15/9C$ 285
Wed 15/106:00 a.m.YHM - SEA
1 stop9h 59mWestJet
Wed 22/101:50 p.m.SEA - YHM
1 stop7h 50mWestJet
Deal found 15/9C$ 286
Thu 13/116:20 a.m.YKF - SEA
1 stop11h 00mWestJet
Wed 19/113:10 p.m.SEA - YKF
1 stop11h 18mWestJet
Deal found 13/9C$ 315
Tue 7/1012:00 p.m.YYZ - SEA
1 stop10h 31mAir Canada
Mon 20/102:55 p.m.SEA - YYZ
1 stop7h 11mAir Canada
Deal found 15/9C$ 315
Wed 15/106:00 a.m.YHM - SEA
1 stop9h 59mWestJet
Thu 23/101:50 p.m.SEA - YHM
1 stop7h 50mWestJet
Deal found 15/9C$ 316
Tue 7/104:00 p.m.YYZ - SEA
2 stops9h 31mMultiple Airlines
Wed 8/101:50 p.m.SEA - YYZ
1 stop7h 32mMultiple Airlines
Deal found 14/9C$ 316
Mon 29/93:35 p.m.YOW - SEA
1 stop7h 54mWestJet
Thu 2/108:40 a.m.SEA - YOW
2 stops12h 42mWestJet
Deal found 15/9C$ 318
Tue 7/106:15 a.m.YYZ - SEA
2 stops11h 01mAir Canada
Tue 21/1010:00 a.m.SEA - YYZ
2 stops9h 05mAir Canada
Deal found 14/9C$ 318
Sat 25/108:00 a.m.YYZ - SEA
1 stop7h 59mMultiple Airlines
Sat 1/117:55 a.m.SEA - YYZ
Nonstop4h 40mMultiple Airlines
Deal found 14/9C$ 319
Tue 11/117:45 a.m.YYZ - SEA
1 stop9h 35mMultiple Airlines
Tue 18/117:55 a.m.SEA - YYZ
Nonstop4h 40mMultiple Airlines
Deal found 13/9C$ 320
Fri 3/106:45 a.m.YYZ - SEA
1 stop8h 50mWestJet
Sun 12/108:40 a.m.SEA - YYZ
1 stop7h 12mWestJet
Deal found 14/9C$ 322

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 September 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

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Tue 21/10

6:00 a.m.-12:59 p.m.

1 stop9h 59m

Seattle/Tacoma Intl

Fri 24/10

1:50 p.m.-12:40 a.m.

1 stop7h 50m

C$ 282

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Wed 15/10

6:00 a.m.-12:59 p.m.

1 stop9h 59m

Seattle/Tacoma Intl

Wed 22/10

1:50 p.m.-12:40 a.m.

1 stop7h 50m

C$ 282

WindsorSeattle

YQG - SEA

YQGSEA

Windsor

Tue 3/3

9:45 a.m.-7:16 p.m.

2 stops12h 31m

Seattle/Tacoma Intl

Thu 5/3

8:15 a.m.-7:14 p.m.

1 stop7h 59m

C$ 307

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 13/11

6:20 a.m.-2:20 p.m.

1 stop11h 00m

Seattle/Tacoma Intl

Wed 19/11

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

1 stop11h 18m

C$ 315

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Wed 15/10

6:00 a.m.-12:59 p.m.

1 stop9h 59m

Seattle/Tacoma Intl

Thu 23/10

1:50 p.m.-12:40 a.m.

1 stop7h 50m

C$ 316

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Mon 3/11

6:40 p.m.-11:11 a.m.

1 stop19h 31m

Seattle/Tacoma Intl

Fri 7/11

8:15 a.m.-3:58 p.m.

Nonstop4h 43m

C$ 333

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 28/10

5:30 p.m.-10:45 p.m.

1 stop8h 15m

Seattle/Tacoma Intl

Tue 4/11

11:50 p.m.-1:43 p.m.

1 stop10h 53m

C$ 334

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 8/10

11:00 a.m.-6:49 p.m.

1 stop10h 49m

Seattle/Tacoma Intl

Wed 15/10

6:55 p.m.-9:19 a.m.

2 stops11h 24m

C$ 334

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 29/10

6:52 a.m.-11:43 a.m.

1 stop7h 51m

Seattle/Tacoma Intl

Tue 4/11

5:05 a.m.-3:02 p.m.

1 stop6h 57m

C$ 334

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 18/11

12:45 p.m.-9:33 p.m.

2 stops11h 48m

Seattle/Tacoma Intl

Sat 22/11

7:13 p.m.-4:02 p.m.

2 stops17h 49m

C$ 334

Flights are sorted by cheapest round-trip flights first.

Deals found on 14/9

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$ 262). Flying from Region of Ontario to Seattle in December is currently the most expensive (average of C$ 353). 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 September 2025.

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 September 2025.

The most flights from CAON to SEA are scheduled on a Sunday (6 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (4 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 8h 15m. 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$ 173. Users have also found prices from C$ 211 and C$ 227 on United 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 Alaska Airlines (90%), Hawaiian Airlines (90%) or Air Tahiti Nui (86%) 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$ 251. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 276 on average, our data indicates C$ 733 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$ 262). Flying from Region of Ontario to Seattle in December is currently the most expensive (average of C$ 353). 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
Bothell
Cashmere
Renton
Olympia
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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Pierre Elliott Trudeau Intl to Spokane flights
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Saskatoon to Portland flights
Halifax to Seattle flights
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Regina to Seattle flights
Pierre Elliott Trudeau Intl to Pasco flights
Fort St. John to Portland flights
St John to Portland flights
Calgary to Spokane 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 15 September 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 183AverageC$ 434FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 278AverageC$ 505FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 322AverageC$ 518FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 343AverageC$ 558FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
DeltaCheapestC$ 377AverageC$ 501FlexibilityNo 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?

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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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