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Cheap flights from Ontario to Seattle from C$ 136

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 20/7. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
20 Apr — 27 Apr1
1 adult

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 April 2025.

Round-trip from

C$ 216

One-way from

C$ 136

Popular in

July

Cheapest in

February

Average price

C$ 551

Good round-trip deal

C$ 487 or less

Good one-way deal

C$ 309 or less
WestJet
  • WestJet
  • 5/6-12/6
  • 2 total stops
  • 17h 49m total
  • Ontario to Seattle
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WestJet
  • WestJet
  • 20/7
  • 1 total stop
  • 9h 58m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 10% potential increase in price (C$ 84 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease (C$ 16 potential savings vs. average RT price).
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Average for round-trip flights in April 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 April 2025.

Thu 5/66:00 a.m.YHM - SEA
1 stop9h 58mWestJet
Thu 12/61:50 p.m.SEA - YHM
1 stop7h 51mWestJet
Deal found 14/4C$ 216
Fri 15/88:00 p.m.YXU - SEA
1 stop27h 28mWestJet
Fri 22/87:35 p.m.SEA - YXU
1 stop6h 39mWestJet
Deal found 15/4C$ 253
Fri 15/86:15 a.m.YXU - SEA
1 stop7h 55mUnited Airlines
Fri 22/85:00 p.m.SEA - YXU
2 stops21h 07mUnited Airlines
Deal found 15/4C$ 278
Sat 3/56:00 a.m.YHM - SEA
1 stop9h 58mMultiple Airlines
Tue 13/56:00 a.m.SEA - YHM
2 stops15h 41mMultiple Airlines
Deal found 13/4C$ 325
Thu 8/56:00 a.m.YKF - SEA
3 stops35h 25mMultiple Airlines
Mon 12/53:20 p.m.SEA - YKF
2 stops30h 26mMultiple Airlines
Deal found 15/4C$ 339
Wed 21/51:30 p.m.YYZ - SEA
1 stop8h 40mWestJet
Wed 28/51:50 p.m.SEA - YYZ
1 stop7h 36mWestJet
Deal found 15/4C$ 339
Tue 27/58:00 a.m.YYZ - SEA
1 stop7h 58mMultiple Airlines
Thu 29/56:00 a.m.SEA - YYZ
2 stops13h 56mMultiple Airlines
Deal found 15/4C$ 341
Mon 11/86:10 a.m.YOW - SEA
1 stop9h 21mWestJet
Wed 20/81:50 p.m.SEA - YOW
1 stop7h 51mWestJet
Deal found 14/4C$ 350
Wed 30/76:00 a.m.YKF - SEA
2 stops33h 31mWestJet
Thu 31/77:35 p.m.SEA - YKF
1 stop26h 11mWestJet
Deal found 13/4C$ 357
Sun 18/56:00 a.m.YXU - SEA
1 stop9h 58mMultiple Airlines
Sun 25/56:25 a.m.SEA - YXU
2 stops19h 49mMultiple Airlines
Deal found 14/4C$ 368
Sun 11/59:55 a.m.YXU - SEA
2 stops12h 42mAir Canada
Thu 15/57:20 a.m.SEA - YXU
2 stops22h 59mAir Canada
Deal found 15/4C$ 381
Tue 6/56:00 p.m.YOW - SEA
1 stop7h 13mAir Canada
Mon 12/511:30 a.m.SEA - YOW
1 stop9h 49mAir Canada
Deal found 14/4C$ 391

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 April 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

Thu 5/6

6:00 a.m.-12:58 p.m.

1 stop9h 58m

Seattle/Tacoma Intl

Thu 12/6

1:50 p.m.-12:41 a.m.

1 stop7h 51m

C$ 216

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 15/8

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

1 stop27h 28m

Seattle/Tacoma Intl

Fri 22/8

7:35 p.m.-5:14 a.m.

1 stop6h 39m

C$ 253

LondonSeattle

YXU - SEA

YXUSEA

London

Fri 15/8

6:15 a.m.-11:10 a.m.

1 stop7h 55m

Seattle/Tacoma Intl

Fri 22/8

5:00 p.m.-5:07 p.m.

2 stops21h 07m

C$ 278

HamiltonSeattle

YHM - SEA

YHMSEA

Hamilton

Sat 3/5

6:00 a.m.-12:58 p.m.

1 stop9h 58m

Seattle/Tacoma Intl

Tue 13/5

6:00 a.m.-12:41 a.m.

2 stops15h 41m

C$ 325

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 8/5

6:00 a.m.-2:25 p.m.

3 stops35h 25m

Seattle/Tacoma Intl

Mon 12/5

3:20 p.m.-12:46 a.m.

2 stops30h 26m

C$ 339

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Wed 21/5

1:30 p.m.-7:10 p.m.

1 stop8h 40m

Seattle/Tacoma Intl

Wed 28/5

1:50 p.m.-12:26 a.m.

1 stop7h 36m

C$ 339

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 27/5

8:00 a.m.-12:58 p.m.

1 stop7h 58m

Seattle/Tacoma Intl

Thu 29/5

6:00 a.m.-10:56 p.m.

2 stops13h 56m

C$ 341

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Mon 11/8

6:10 a.m.-12:31 p.m.

1 stop9h 21m

Seattle/Tacoma Intl

Wed 20/8

1:50 p.m.-12:41 a.m.

1 stop7h 51m

C$ 350

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Wed 30/7

6:00 a.m.-12:31 p.m.

2 stops33h 31m

Seattle/Tacoma Intl

Thu 31/7

7:35 p.m.-12:46 a.m.

1 stop26h 11m

C$ 357

LondonSeattle

YXU - SEA

YXUSEA

London

Sun 18/5

6:00 a.m.-12:58 p.m.

1 stop9h 58m

Seattle/Tacoma Intl

Sun 25/5

6:25 a.m.-5:14 a.m.

2 stops19h 49m

C$ 368

Flights are sorted by cheapest round-trip flights first.

Deals found on 14/4

Showing 1-10 of 56 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$ 261). 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 April 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 April 2025.

The most flights from CAON to SEA are scheduled on a Monday (5 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (2 on average).

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 18.0 - 168.0 mm per month. November is typically the wettest month, when rainfall can reach 168.0 mm. July is typically the driest time to visit Seattle when rainfall is around 18.0 mm.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 19.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 5.0 C).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated 15 April 2025.
Read reviews from past customers who have flown Alaska Airlines, Delta and Hawaiian Airlines from Ontario to Seattle. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Overall

8.0

Comfort

7.9

Crew

8.5

Food

7.1

Entertainment

7.1

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
Alaska Airlines
8.0
Very good
9,876 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Overall

8.0

Comfort

7.9

Crew

8.5

Food

7.1

Entertainment

7.1

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
Delta
8.0
Very good
7,917 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Overall

8.0

Comfort

7.9

Crew

8.5

Food

7.1

Entertainment

7.1

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
Hawaiian Airlines
7.9
Good
2,374 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Overall

8.0

Comfort

7.9

Crew

8.5

Food

7.1

Entertainment

7.1

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
United Airlines
7.4
Good
8,658 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Overall

8.0

Comfort

7.9

Crew

8.5

Food

7.1

Entertainment

7.1

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Overall

8.0

Comfort

7.9

Crew

8.5

Food

7.1

Entertainment

7.1

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

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.

  • 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$ 136. Users have also found prices from C$ 170 and C$ 182 on Air Canada 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 (99%), Alaska Airlines (85%) or Hawaiian Airlines (85%) 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$ 241. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 324 on average our data indicates C$ 1,345 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$ 261). 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 Ontario?

Book flights to Ontario if you plan to visit one of these locations
SeaTac
Tukwila
Marysville
Bothell
Leavenworth
Tacoma
Olympia
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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Top 7 airlines flying from Ontario to Seattle

Discover the top 7 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 April 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 192AverageC$ 460FlexibilityNo cancel feeOn-time60%
Search WestJet flights
Alaska AirlinesCheapestC$ 332AverageC$ 517FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 363AverageC$ 525FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
United AirlinesCheapestC$ 367AverageC$ 637FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
DeltaCheapestC$ 407AverageC$ 569FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Hawaiian AirlinesCheapestC$ 413AverageC$ 413FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights
American AirlinesCheapestC$ 431AverageC$ 555FlexibilityNo cancel feeOn-time71%
Search American Airlines flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.

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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