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Cheap flights from Ontario to Seattle from C$ 288

YYZ — SEA
19 Nov — 26 Nov1
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

Wed 18/117:30 a.m. -
1 stop9h 10m
Wed 9/122:30 p.m. -
2 stops12h 15m
Deal found 20/10C$ 456
Sat 21/117:30 a.m. -
1 stop9h 10m
Sat 28/112:20 p.m. -
2 stops12h 25m
Deal found 19/10C$ 460
Thu 17/126:10 a.m. -
1 stop10h 30m
Wed 13/12:30 p.m. -
2 stops12h 15m
Deal found 20/10C$ 461
Fri 4/126:10 a.m. -
1 stop10h 30m
Fri 11/122:30 p.m. -
2 stops12h 15m
Deal found 20/10C$ 463
Tue 17/117:30 a.m. -
1 stop9h 10m
Wed 9/122:30 p.m. -
2 stops12h 15m
Deal found 20/10C$ 471
Tue 17/117:30 a.m. -
1 stop9h 10m
Tue 24/112:30 p.m. -
2 stops12h 15m
Deal found 20/10C$ 477
Tue 17/117:30 a.m. -
1 stop9h 10m
Thu 10/122:30 p.m. -
2 stops12h 15m
Deal found 20/10C$ 478
Thu 19/117:30 a.m. -
1 stop9h 10m
Wed 9/122:30 p.m. -
2 stops12h 15m
Deal found 20/10C$ 481
Tue 24/117:30 a.m. -
1 stop9h 10m
Mon 7/122:30 p.m. -
1 stop11h 30m
Deal found 17/10C$ 482
Thu 19/113:25 p.m. -
1 stop25h 15m
Mon 23/112:30 p.m. -
1 stop20h 55m
Deal found 15/10C$ 574
Thu 3/126:10 a.m. -
1 stop10h 30m
Mon 7/122:30 p.m. -
1 stop21h 00m
Deal found 16/10C$ 578
Mon 14/126:10 a.m. -
1 stop10h 30m
Fri 12/211:00 a.m. -
2 stops9h 40m
Deal found 16/10C$ 579

Find flight deals from Ontario to Seattle

Round-trip from

C$ 456

One-way from

C$ 288

Popular in

June

Cheapest in

February

Average price

C$ 613

Good round-trip deal

C$ 715 or less

Good one-way deal

C$ 404 or less
WestJet
  • WestJet
  • 18/11-9/12
  • 3 total stops
  • 21h 25m total
  • Ontario to Seattle
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WestJet
  • WestJet
  • 16/2-31/12
  • 1 total stop
  • 10h 30m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 6% potential increase in price (C$ 57 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease (C$ 17 potential savings vs. average RT price).
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Average for round-trip flights in October 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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Cheapflights Fare Finder

 
Use the filters below to find and compare flights from Ontario to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

HamiltonSeattle

YHM Hamilton - SEA Seattle/Tacoma Intl

YHMSEA

Hamilton

Sun 22/11

3:25 p.m.-1:40 p.m.

1 stop25h 15m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 338

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Thu 3/12

6:10 a.m.-1:40 p.m.

1 stop10h 30m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 342

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Tue 3/11

6:10 a.m.-1:40 p.m.

1 stop10h 30m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 342

LondonSeattle

YXU London - SEA Seattle/Tacoma Intl

YXUSEA

London

Thu 3/12

6:40 a.m.-1:40 p.m.

1 stop10h 00m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 377

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Fri 22/1

6:15 a.m.-11:15 p.m.

2 stops20h 00m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 377

LondonSeattle

YXU London - SEA Seattle/Tacoma Intl

YXUSEA

London

Thu 3/12

10:00 a.m.-12:27 p.m.

3 stops29h 27m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 378

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Sat 21/11

5:15 p.m.-7:47 p.m.

Nonstop5h 32m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 384

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Sat 19/12

5:15 p.m.-8:13 p.m.

Nonstop5h 58m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 384

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Sat 5/12

6:15 a.m.-11:44 a.m.

1 stop8h 29m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 391

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Fri 25/12

5:15 p.m.-8:13 p.m.

Nonstop5h 58m

Seattle/Tacoma Intl

Wed 31/12

12:00 a.m.-3:00 a.m.

Nonstop0h 00m

C$ 399

Flights are sorted by cheapest round-trip flights first.

Deals found on 18/10

Showing 1-10 of 60 resultsSorted by cheapest first
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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

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, February is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 354). Flying from Region of Ontario to Seattle in December is currently the most expensive (average of C$ 669). 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?

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.

How much does it cost to fly round-trip from Region of Ontario to Seattle?

Airfare is below average for this route at the moment.
Region of Ontario to Seattle flights typically cost between C$ 453 and C$ 753 in February.
The cheapest round-trip price found within the last 5 days was C$ 450 on WestJet (28 Feb-5 Mar).

How far ahead should I book a flight from Region of Ontario to Seattle?

Booking 72 days in advance of your planned departure date is, on average, the best time to get cheap flights from Region of Ontario to Seattle. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

Related info for your journey

  • 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 30m. 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$ 123. Users have also found prices from C$ 154 and C$ 172 on Air Canada and Alaska 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 Toronto Island - 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 Qatar Airways (100%), Alaska Airlines (83%) or Brussels Airlines (44%) 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$ 331. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 564 on average, our data indicates C$ 706 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, February is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of C$ 354). Flying from Region of Ontario to Seattle in December is currently the most expensive (average of C$ 669). 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
SeaTac
Kent
Mukilteo
Ellensburg
Renton
Lynnwood
Cashmere
Leavenworth
Tukwila
Tacoma
Marysville
Federal Way
Kirkland

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for Ontario to Seattle

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Top 5 airlines flying from Ontario to Seattle

AirlineCheapestAverageFlexibilityOn-time
DeltaCheapestC$ 228AverageC$ 852FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air CanadaCheapestC$ 254AverageC$ 674FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
United AirlinesCheapestC$ 256AverageC$ 790FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 272AverageC$ 484FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
WestJetCheapestC$ 300AverageC$ 536FlexibilityNo cancel feeOn-time60%
Search WestJet flights

Fly with Cheapflights

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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