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Cheap flights from Ontario to Seattle from C$ 164

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 1/6. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
4 May — 11 May1
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 29 April 2025.

Round-trip from

C$ 267

One-way from

C$ 164

Popular in

July

Cheapest in

February

Average price

C$ 549

Good round-trip deal

C$ 426 or less

Good one-way deal

C$ 301 or less
WestJet
  • WestJet
  • 18/5-30/5
  • 2 total stops
  • 17h 49m total
  • Ontario to Seattle
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WestJet
  • WestJet
  • 1/6
  • 1 total stop
  • 9h 58m total
  • Ontario to Seattle
Search Deals
Highest demand for flights based on searches. 10% potential increase in price (C$ 82 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease (C$ 15 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 29 April 2025.

Sun 18/56:00 a.m.YHM - SEA
1 stop9h 58mWestJet
Fri 30/51:50 p.m.SEA - YHM
1 stop7h 51mWestJet
Deal found 28/4C$ 267
Thu 24/76:00 a.m.YKF - SEA
1 stop17h 28mWestJet
Sat 26/71:50 p.m.SEA - YKF
1 stop7h 56mWestJet
Deal found 28/4C$ 324
Tue 3/64:45 p.m.YYZ - SEA
Nonstop5h 19mAlaska Airlines
Fri 6/67:23 a.m.SEA - YYZ
Nonstop4h 37mAlaska Airlines
Deal found 28/4C$ 360
Thu 5/612:00 p.m.YYZ - SEA
1 stop10h 37mAir Canada
Wed 11/61:45 p.m.SEA - YYZ
1 stop8h 24mAir Canada
Deal found 28/4C$ 362
Sun 1/68:00 a.m.YYZ - SEA
1 stop7h 58mWestJet
Sun 8/62:05 p.m.SEA - YYZ
2 stops12h 46mWestJet
Deal found 28/4C$ 366
Sun 25/58:25 a.m.YYZ - SEA
Nonstop5h 20mUnited Airlines
Wed 4/67:27 p.m.SEA - YYZ
1 stop8h 33mUnited Airlines
Deal found 28/4C$ 374
Fri 6/611:40 a.m.YYZ - SEA
1 stop11h 23mAmerican Airlines
Mon 9/612:05 a.m.SEA - YYZ
1 stop9h 35mAmerican Airlines
Deal found 28/4C$ 395
Sun 25/56:00 a.m.YKF - SEA
1 stop9h 58mMultiple Airlines
Wed 4/66:00 a.m.SEA - YKF
2 stops15h 46mMultiple Airlines
Deal found 28/4C$ 396
Wed 28/56:00 a.m.YOW - SEA
1 stop9h 58mWestJet
Wed 11/67:05 a.m.SEA - YOW
1 stop8h 16mWestJet
Deal found 28/4C$ 409
Sun 25/512:25 p.m.YTZ - SEA
1 stop10h 12mAir Canada
Wed 4/67:20 a.m.SEA - YTZ
1 stop11h 15mAir Canada
Deal found 28/4C$ 412
Thu 29/55:50 p.m.YYZ - SEA
1 stop9h 09mDelta
Mon 2/611:50 p.m.SEA - YYZ
1 stop8h 50mDelta
Deal found 27/4C$ 412
Wed 4/62:00 p.m.YYZ - SEA
2 stops27h 25mMultiple Airlines
Wed 11/66:00 a.m.SEA - YYZ
3 stops20h 51mMultiple Airlines
Deal found 28/4C$ 420

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 29 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

Sun 18/5

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

1 stop9h 58m

Seattle/Tacoma Intl

Fri 30/5

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

1 stop7h 51m

C$ 267

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Thu 24/7

6:00 a.m.-8:28 p.m.

1 stop17h 28m

Seattle/Tacoma Intl

Sat 26/7

1:50 p.m.-12:46 a.m.

1 stop7h 56m

C$ 324

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Tue 3/6

4:45 p.m.-7:04 p.m.

Nonstop5h 19m

Seattle/Tacoma Intl

Fri 6/6

7:23 a.m.-3:00 p.m.

Nonstop4h 37m

C$ 360

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 5/6

12:00 p.m.-7:37 p.m.

1 stop10h 37m

Seattle/Tacoma Intl

Wed 11/6

1:45 p.m.-1:09 a.m.

1 stop8h 24m

C$ 362

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 1/6

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

1 stop7h 58m

Seattle/Tacoma Intl

Sun 8/6

2:05 p.m.-5:51 a.m.

2 stops12h 46m

C$ 366

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Sun 25/5

8:25 a.m.-10:45 a.m.

Nonstop5h 20m

Seattle/Tacoma Intl

Wed 4/6

7:27 p.m.-7:00 a.m.

1 stop8h 33m

C$ 374

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Fri 6/6

11:40 a.m.-8:03 p.m.

1 stop11h 23m

Seattle/Tacoma Intl

Mon 9/6

12:05 a.m.-12:40 p.m.

1 stop9h 35m

C$ 395

TorontoSeattle

YKF - SEA

YKFSEA

Toronto Region of Waterloo Intl

Sun 25/5

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

1 stop9h 58m

Seattle/Tacoma Intl

Wed 4/6

6:00 a.m.-12:46 a.m.

2 stops15h 46m

C$ 396

OttawaSeattle

YOW - SEA

YOWSEA

Ottawa

Wed 28/5

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

1 stop9h 58m

Seattle/Tacoma Intl

Wed 11/6

7:05 a.m.-6:21 p.m.

1 stop8h 16m

C$ 409

TorontoSeattle

YYZ - SEA

YYZSEA

Toronto Pearson Intl

Thu 29/5

5:50 p.m.-11:59 p.m.

1 stop9h 09m

Seattle/Tacoma Intl

Mon 2/6

11:50 p.m.-11:40 a.m.

1 stop8h 50m

C$ 412

Flights are sorted by cheapest round-trip flights first.

Deals found on 28/4

Showing 1-10 of 54 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 29 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 29 April 2025.

The most flights from CAON to SEA are scheduled on a Thursday (7 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (4 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 29 April 2025.
Read reviews from past customers who have flown Alaska Airlines, Delta and United 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
9,949 reviews
Check prices

Entertainment

7.1

Comfort

7.9

Boarding

8.2

Food

7.1

Crew

8.5

Overall

8.0

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
9,949 reviews
Alaska Airlines
8.0
Very good
9,949 reviews
Check prices

Entertainment

7.1

Comfort

7.9

Boarding

8.2

Food

7.1

Crew

8.5

Overall

8.0

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
7,929 reviews
Alaska Airlines
8.0
Very good
9,949 reviews
Check prices

Entertainment

7.1

Comfort

7.9

Boarding

8.2

Food

7.1

Crew

8.5

Overall

8.0

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
8,696 reviews
Alaska Airlines
8.0
Very good
9,949 reviews
Check prices

Entertainment

7.1

Comfort

7.9

Boarding

8.2

Food

7.1

Crew

8.5

Overall

8.0

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
9,949 reviews
Check prices

Entertainment

7.1

Comfort

7.9

Boarding

8.2

Food

7.1

Crew

8.5

Overall

8.0

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
WestJet
7.2
Good
2,823 reviews
Alaska Airlines
8.0
Very good
9,949 reviews
Check prices

Entertainment

7.1

Comfort

7.9

Boarding

8.2

Food

7.1

Crew

8.5

Overall

8.0

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$ 164. Users have also found prices from C$ 215 and C$ 243 on United Airlines and American 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 (95%), Alaska Airlines (87%) or Hawaiian Airlines (87%) 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$ 235. While the most popular route (Toronto Pearson Intl - Seattle/Tacoma Intl) can be booked for C$ 374 on average our data indicates C$ 1,092 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
Tukwila
SeaTac
Tacoma
Marysville
Bothell
Olympia
Lynnwood
Leavenworth

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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 Seattle flights
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Edmonton to Portland flights
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Saskatoon to Portland flights
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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 29 April 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapestC$ 183AverageC$ 450FlexibilityNo cancel feeOn-time60%
Search WestJet flights
United AirlinesCheapestC$ 279AverageC$ 502FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Alaska AirlinesCheapestC$ 331AverageC$ 506FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Air CanadaCheapestC$ 362AverageC$ 517FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
DeltaCheapestC$ 375AverageC$ 565FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
Hawaiian AirlinesCheapestC$ 412AverageC$ 412FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights
American AirlinesCheapestC$ 429AverageC$ 553FlexibilityNo 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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