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Cheap flights from Seattle to Ontario from C$ 96

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 29/5. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YYZ
20 abr. — 27 abr.1
1 adult

Cheap flight deals from Seattle to Ontario

Keep the following information in mind while searching for Seattle to Ontario flight deals. Data was last updated 15 abril 2025.

Round-trip from

C$ 231

One-way from

C$ 96

Popular in

June

Cheapest in

January

Average price

C$ 619

Good round-trip deal

C$ 501 or less

Good one-way deal

C$ 223 or less
WestJet
  • WestJet
  • 5/5-12/5
  • 2 total stops
  • 17h 43m total
  • Seattle to Ontario
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WestJet
  • WestJet
  • 29/5
  • 1 total stop
  • 7h 51m total
  • Seattle to Ontario
Search Deals
Highest demand for flights based on searches. 14% potential increase in price (C$ 142 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 Seattle/Tacoma Intl to Ontario.
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Price to beat on a one-way flight from Seattle/Tacoma Intl to Ontario.
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Find flight deals from Seattle to Ontario

Cheapest flights from Seattle to Ontario
Explore the most affordable flight options available from Seattle to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 15 abril 2025.

lun. 5/58:25 a.m.SEA - YXU
1 stop7h 45mWestJet
lun. 12/56:00 a.m.YXU - SEA
1 stop9h 58mWestJet
Deal found 15/4C$ 231
jue. 29/51:50 p.m.SEA - YHM
1 stop7h 51mWestJet
dom. 1/66:00 a.m.YHM - SEA
1 stop9h 58mWestJet
Deal found 15/4C$ 234
sáb. 31/511:30 a.m.SEA - YXU
1 stop6h 58mUnited Airlines
sáb. 7/66:15 a.m.YXU - SEA
1 stop7h 36mUnited Airlines
Deal found 15/4C$ 293
sáb. 31/511:30 a.m.SEA - YXU
1 stop6h 58mAir Canada
sáb. 7/69:55 a.m.YXU - SEA
2 stops13h 42mAir Canada
Deal found 15/4C$ 299
jue. 29/56:00 a.m.SEA - YHM
2 stops15h 41mMultiple Airlines
jue. 5/66:00 a.m.YHM - SEA
1 stop9h 58mMultiple Airlines
Deal found 14/4C$ 307
dom. 25/510:10 a.m.SEA - YKF
2 stops11h 36mMultiple Airlines
mié. 28/56:00 a.m.YKF - SEA
1 stop9h 58mMultiple Airlines
Deal found 15/4C$ 328
vie. 22/81:15 p.m.SEA - YKF
2 stops32h 31mWestJet
sáb. 30/86:00 a.m.YKF - SEA
1 stop9h 58mWestJet
Deal found 13/4C$ 330
lun. 12/56:00 a.m.SEA - YYZ
2 stops21h 14mMultiple Airlines
mar. 20/512:45 p.m.YYZ - SEA
1 stop10h 57mMultiple Airlines
Deal found 14/4C$ 332
vie. 6/61:50 p.m.SEA - YYZ
1 stop7h 34mWestJet
mar. 10/612:00 p.m.YYZ - SEA
2 stops11h 28mWestJet
Deal found 14/4C$ 364
vie. 30/51:50 p.m.SEA - YOW
2 stops12h 35mMultiple Airlines
vie. 6/62:25 p.m.YOW - SEA
1 stop9h 12mMultiple Airlines
Deal found 15/4C$ 368
lun. 5/58:22 p.m.SEA - YXU
2 stops19h 48mMultiple Airlines
lun. 12/56:00 a.m.YXU - SEA
1 stop9h 58mMultiple Airlines
Deal found 15/4C$ 373
vie. 6/61:50 p.m.SEA - YOW
1 stop7h 51mWestJet
dom. 8/66:10 a.m.YOW - SEA
1 stop9h 21mWestJet
Deal found 15/4C$ 382

Cheapflights Fare Finder

Customize your flight search to find flights from Seattle to Ontario 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 abril 2025.
Use the filters below to find and compare flights from Seattle to Ontario that are best for you.

Fly from

Seattle

Fly to

Ontario

Route

Depart

Return

Price

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

lun. 5/5

8:25 a.m.-7:10 p.m.

1 stop7h 45m

London

lun. 12/5

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

1 stop9h 58m

C$ 231

SeattleHamilton

SEA - YHM

SEAYHM

Seattle/Tacoma Intl

jue. 29/5

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

1 stop7h 51m

Hamilton

dom. 1/6

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

1 stop9h 58m

C$ 234

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

sáb. 31/5

11:30 a.m.-9:28 p.m.

1 stop6h 58m

London

sáb. 7/6

6:15 a.m.-10:51 a.m.

1 stop7h 36m

C$ 293

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

sáb. 31/5

11:30 a.m.-9:28 p.m.

1 stop6h 58m

London

sáb. 7/6

9:55 a.m.-8:37 p.m.

2 stops13h 42m

C$ 299

SeattleHamilton

SEA - YHM

SEAYHM

Seattle/Tacoma Intl

jue. 29/5

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

2 stops15h 41m

Hamilton

jue. 5/6

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

1 stop9h 58m

C$ 307

SeattleToronto

SEA - YKF

SEAYKF

Seattle/Tacoma Intl

dom. 25/5

10:10 a.m.-12:46 a.m.

2 stops11h 36m

Toronto Region of Waterloo Intl

mié. 28/5

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

1 stop9h 58m

C$ 328

SeattleToronto

SEA - YKF

SEAYKF

Seattle/Tacoma Intl

vie. 22/8

1:15 p.m.-12:46 a.m.

2 stops32h 31m

Toronto Region of Waterloo Intl

sáb. 30/8

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

1 stop9h 58m

C$ 330

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

lun. 12/5

6:00 a.m.-6:14 a.m.

2 stops21h 14m

Toronto Pearson Intl

mar. 20/5

12:45 p.m.-8:42 p.m.

1 stop10h 57m

C$ 332

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

vie. 6/6

1:50 p.m.-12:24 a.m.

1 stop7h 34m

Toronto Pearson Intl

mar. 10/6

12:00 p.m.-8:28 p.m.

2 stops11h 28m

C$ 364

SeattleOttawa

SEA - YOW

SEAYOW

Seattle/Tacoma Intl

vie. 30/5

1:50 p.m.-5:25 a.m.

2 stops12h 35m

Ottawa

vie. 6/6

2:25 p.m.-8:37 p.m.

1 stop9h 12m

C$ 368

Flights are sorted by cheapest round-trip flights first.

Deals found on 14/4

Showing 1-10 of 55 results
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Best time to book a flight from Seattle to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Seattle 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 Seattle to Ontario

What is the cheapest month to book a flight from Seattle to Region of Ontario?

Currently, January is the cheapest month in which you can book a flight from Seattle to Region of Ontario (average of C$ 167). Flying from Seattle to Region of Ontario in July is currently the most expensive (average of C$ 258). 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 SEA to ON?

Find hourly flight availability from Seattle to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 15 abril 2025.

When flying from Seattle to Region of Ontario, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Weekly flight availability from Seattle to Region of Ontario

Explore weekly flight availability from Seattle to Ontario. 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 abril 2025.

The most flights from SEA to CAON are scheduled on a Tuesday (6 on average). You will have fewer flight options on Friday, which is when the least amount of flights are scheduled (2 on average).

Rainfall in Ontario by month

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

In terms of precipitation, rainfall in Region of Ontario ranges from 51.0 - 83.0 mm per month. June is typically the wettest month, when rainfall can reach 83.0 mm. February is typically the driest time to visit Region of Ontario when rainfall is around 51.0 mm.

Temperature in Ontario by month

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

If weather is an important factor for your trip to Region of Ontario, 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 21.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around -6.0 C).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated 15 abril 2025.
Read through reviews of airlines operating flights from Seattle to Ontario, such as Alaska Airlines, Delta and United Airlines. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Comfort

7.9

Food

7.1

Crew

8.5

Boarding

8.2

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
Alaska Airlines
8.0
Very good
9,876 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Comfort

7.9

Food

7.1

Crew

8.5

Boarding

8.2

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
Delta
8.0
Very good
7,917 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Comfort

7.9

Food

7.1

Crew

8.5

Boarding

8.2

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
United Airlines
7.4
Good
8,658 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Comfort

7.9

Food

7.1

Crew

8.5

Boarding

8.2

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Comfort

7.9

Food

7.1

Crew

8.5

Boarding

8.2

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
WestJet
7.2
Good
2,805 reviews
Alaska Airlines
8.0
Very good
9,876 reviews
Check prices

Comfort

7.9

Food

7.1

Crew

8.5

Boarding

8.2

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥

Related info for your journey

Find useful and relevant information for your journey from Seattle to Ontario. 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 from for flights from Seattle to Ontario?

    Located just 18.4 km from the city centre, Seattle/Tacoma Intl (SEA) is the airport most travellers will use when flying to Ontario from Seattle.

  • What are the cheapest airlines to fly from Seattle to Region of Ontario one-way?

    The cheapest airlines for a one-way flight from Seattle to Region of Ontario are WestJet (C$ 96), Alaska Airlines (C$ 204), and Air Canada (C$ 206).

  • What are the most popular routes from Seattle to Region of Ontario?

    When deciding which route to take from Seattle to Region of Ontario consider Seattle/Tacoma Intl - Toronto Pearson Intl, Seattle/Tacoma Intl - Montreal Pierre Elliott Trudeau Intl or Seattle/Tacoma Intl - Toronto Island as they are the most popular.

  • What are the most reliable airlines from Seattle to Region of Ontario?

    Consider Air Tahiti Nui (100%), Brussels Airlines (100%) or Alaska Airlines (90%) when booking your flight. These represent the most reliable airlines when flying from Seattle to Region of Ontario.

  • What are the cheapest flights from Seattle to Region of Ontario?

    The cheapest flight price from Seattle to Region of Ontario is C$ 223. On average you can expect to pay C$ 492. The most popular route, (Seattle/Tacoma Intl - Toronto Pearson Intl), can usually be booked for C$ 339.

  • Can I find deals for flights from Seattle to Ontario that include hotel bookings?

    Yes. In addition to deals on Seattle to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Ontario.

  • Can I find deals for business class flights from Seattle to Ontario?

    Yes. Cheapflights offers flight deals from Seattle to Ontario 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 Seattle to Region of Ontario?

    Currently, January is the cheapest month in which you can book a flight from Seattle to Region of Ontario (average of C$ 167). Flying from Seattle to Region of Ontario in July is currently the most expensive (average of C$ 258). 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

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Alternative routes for Seattle to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Bellingham to Pearson Intl flights
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Top 3 airlines flying from Seattle to Ontario

Discover the top 3 airlines that operate flights from Seattle to Ontario. 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 abril 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 226AverageC$ 792FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
WestJetCheapestC$ 299AverageC$ 419FlexibilityNo cancel feeOn-time60%
Search WestJet flights
Alaska AirlinesCheapestC$ 394AverageC$ 669FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights

Fly with Cheapflights

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How does Cheapflights help users find flights from Seattle to Ontario?

Cheapflights goes through 900+ travel sites to look for the best flight deals for flights from Seattle to Ontario. Too many options? Cheapflights also provides filters for things like airlines, price ranges, and number of stops to help you make a decision easily.

Why should you use Cheapflights to find cheap flight tickets from Seattle to Ontario?

Cheapflights simply makes it quick and affordable to book flights from Seattle to Ontario by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.

Can Cheapflights find flights from Seattle to Ontario with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights from Seattle to Ontario flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights from Seattle to Ontario become cheaper?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

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