Find flights
Deals
When to book
FAQs

Cheap flights from Ontario to Seattle from C$ 295

YYZ — SEA
15 Nov — 22 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

Thu 26/117:30 a.m. -
1 stop9h 10m
Thu 3/122:30 p.m. -
2 stops12h 15m
Deal found 12/10C$ 444
Wed 25/117:30 a.m. -
1 stop9h 10m
Wed 2/122:30 p.m. -
2 stops12h 15m
Deal found 11/10C$ 452
Thu 12/117:30 a.m. -
1 stop9h 10m
Sun 22/112:30 p.m. -
2 stops12h 15m
Deal found 15/10C$ 460
Thu 26/117:30 a.m. -
1 stop9h 10m
Fri 4/122:30 p.m. -
2 stops12h 15m
Deal found 10/10C$ 461
Tue 3/117:30 a.m. -
1 stop9h 10m
Tue 10/112:30 p.m. -
2 stops12h 15m
Deal found 13/10C$ 463
Fri 13/116:10 a.m. -
1 stop10h 30m
Thu 3/122:30 p.m. -
2 stops12h 15m
Deal found 14/10C$ 467
Thu 19/117:30 a.m. -
1 stop9h 10m
Mon 23/112:30 p.m. -
2 stops12h 15m
Deal found 13/10C$ 469
Wed 11/117:30 a.m. -
1 stop9h 10m
Wed 2/122:30 p.m. -
2 stops12h 15m
Deal found 14/10C$ 470
Wed 16/127:00 a.m. -
2 stops9h 40m
Wed 13/12:30 p.m. -
1 stop20h 40m
Deal found 15/10C$ 471
Thu 26/117:30 a.m. -
1 stop9h 10m
Mon 30/112:30 p.m. -
2 stops12h 15m
Deal found 10/10C$ 473
Tue 24/117:30 a.m. -
1 stop9h 10m
Fri 27/112:30 p.m. -
2 stops12h 15m
Deal found 13/10C$ 476
Tue 24/117:30 a.m. -
1 stop9h 10m
Tue 1/122:30 p.m. -
2 stops12h 15m
Deal found 10/10C$ 477

Find flight deals from Ontario to Seattle

Round-trip from

C$ 444

One-way from

C$ 295

Popular in

June

Cheapest in

February

Average price

C$ 606

Good round-trip deal

C$ 712 or less

Good one-way deal

C$ 414 or less
WestJet
  • WestJet
  • 26/11-3/12
  • 3 total stops
  • 21h 25m total
  • Ontario to Seattle
Search Deals
WestJet
  • WestJet
  • 10/11-31/12
  • 1 total stop
  • 9h 10m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 8% potential increase in price (C$ 69 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 18 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 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

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

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Wed 17/2

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$ 314

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Tue 17/11

6:00 a.m.-2:50 p.m.

1 stop11h 50m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 324

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Thu 26/11

7:45 a.m.-2:37 p.m.

1 stop9h 52m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 328

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Sat 5/12

7:50 a.m.-6:22 p.m.

2 stops13h 32m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 365

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Sat 5/12

9:45 a.m.-6:24 p.m.

2 stops11h 39m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 373

OttawaSeattle

YOW Ottawa - SEA Seattle/Tacoma Intl

YOWSEA

Ottawa

Tue 1/12

5:30 a.m.-1:40 p.m.

2 stops35h 10m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 382

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Tue 1/12

5:15 p.m.-7:56 p.m.

Nonstop5h 41m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 388

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Wed 11/11

5:15 p.m.-7:45 p.m.

Nonstop5h 30m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 388
Quickest round-trip

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Sat 9/1

5:15 p.m.-7:42 p.m.

Nonstop5h 27m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 403

TorontoSeattle

YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl

YYZSEA

Toronto Pearson Intl

Mon 16/11

5:15 p.m.-7:45 p.m.

Nonstop5h 30m

Seattle/Tacoma Intl

Wed 31/12

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

Nonstop0h 00m

C$ 403

Flights are sorted by cheapest round-trip flights first.

Deals found on 14/10

Showing 1-10 of 60 resultsSorted by cheapest first
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

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$ 672). 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$ 511 and C$ 825 in November.
The cheapest round-trip price found within the last 5 days was C$ 444 on WestJet (26 Nov-3 Dec).

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

Booking 74 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 8h 10m. 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$ 125. Users have also found prices from C$ 155 and C$ 174 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 Ottawa - 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 Alaska Airlines (83%), Brussels Airlines (38%) or Air Canada (33%) 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$ 348. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 551 on average, our data indicates C$ 740 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$ 672). 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
Renton
Lynnwood
Cashmere
Ellensburg
Leavenworth
Tukwila
Tacoma
Marysville
Federal Way
Kirkland

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for Ontario to Seattle

Pearson Intl to Seattle flights
Vancouver Intl to Seattle flights
Vancouver Intl to Portland flights
Ottawa to Seattle flights
Calgary to Seattle flights
Hamilton to Seattle flights
Edmonton to Seattle flights
Toronto Island to Seattle flights
Pierre Elliott Trudeau Intl to Seattle flights
Kelowna to Seattle flights
Victoria to Seattle flights
Pierre Elliott Trudeau Intl to Portland flights
Pearson Intl to Portland flights
London to Seattle flights
Calgary to Portland flights
Toronto Island to Portland flights
Edmonton to Portland flights
Kelowna to Portland flights
Prince George to Seattle flights
Vancouver Intl to Pullman flights
Kamloops to Portland flights
Calgary to Spokane flights
Saskatoon to Seattle flights
Winnipeg to Seattle flights
Vancouver Intl to Spokane flights
Victoria to Portland flights
Ottawa to Portland flights
Hamilton to Portland flights
Winnipeg to Portland flights
Saskatoon to Portland flights
Halifax to Seattle flights
Pearson Intl to Spokane flights
Nanaimo to Portland flights
Pearson Intl to Pasco flights
Regina to Seattle flights
Québec City to Seattle flights
Pierre Elliott Trudeau Intl to Spokane flights
Vancouver Intl to Bellingham flights
Québec City to Portland flights
Fort St. John to Portland flights
Region of Waterloo Intl to Seattle flights
Pierre Elliott Trudeau Intl to Pasco flights
Regina to Portland flights
London to Portland flights
Thunder Bay to Portland flights
Fort St. John to Spokane flights

Top 5 airlines flying from Ontario to Seattle

AirlineCheapestAverageFlexibilityOn-time
DeltaCheapestC$ 230AverageC$ 858FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Air CanadaCheapestC$ 257AverageC$ 672FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
United AirlinesCheapestC$ 258AverageC$ 778FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 275AverageC$ 480FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
WestJetCheapestC$ 303AverageC$ 541FlexibilityNo 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.

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.