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Cheap flights from Seattle to Ontario from C$ 159

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 23/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YYZ
26 Feb — 5 Mar1
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 21 February 2025.

Round-trip from

C$ 293

One-way from

C$ 159

Popular in

April

Cheapest in

January

Average price

C$ 459

Good round-trip deal

C$ 806 or less

Good one-way deal

C$ 171 or less
2/4-8/4
  • 2/4-8/4
  • 2 total stops
  • 36h 30m total
  • Seattle to Ontario
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23/3
  • 23/3
  • 2 total stops
  • 31h 41m total
  • Seattle to Ontario
Search Deals
Highest demand for flights based on searches. 14% potential increase in price (C$ 162 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease (C$ 31 potential savings vs. average RT price).
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Average for round-trip flights in February 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 21 February 2025.

Wed 2/49:48 a.m.SEA - YYZ
1 stop17h 55mMultiple Airlines
Tue 8/48:00 p.m.YYZ - SEA
1 stop18h 35mMultiple Airlines
Deal found 20/2C$ 293
Mon 7/43:15 p.m.SEA - YKF
1 stop7h 01mWestJet
Tue 8/46:30 a.m.YKF - SEA
1 stop10h 51mWestJet
Deal found 20/2C$ 341
Tue 11/311:48 a.m.SEA - YOW
1 stop25h 57mMultiple Airlines
Mon 17/36:10 p.m.YOW - SEA
1 stop20h 36mMultiple Airlines
Deal found 19/2C$ 375
Sun 6/411:30 a.m.SEA - YKF
2 stops10h 46mMultiple Airlines
Sun 13/49:05 p.m.YKF - SEA
1 stop20h 16mMultiple Airlines
Deal found 20/2C$ 388
Thu 22/57:05 a.m.SEA - YYZ
1 stop7h 17mWestJet
Mon 16/61:30 p.m.YYZ - SEA
1 stop9h 58mWestJet
Deal found 18/2C$ 391
Wed 28/51:50 p.m.SEA - YHM
1 stop7h 51mWestJet
Sun 8/66:00 a.m.YHM - SEA
1 stop9h 58mWestJet
Deal found 20/2C$ 401
Thu 3/46:05 a.m.SEA - YYZ
Nonstop4h 55mAir Canada
Thu 10/47:05 p.m.YYZ - SEA
Nonstop5h 21mAir Canada
Deal found 19/2C$ 415
Sat 5/45:45 a.m.SEA - YTZ
2 stops11h 52mAir Canada
Sat 12/44:20 p.m.YTZ - SEA
2 stops8h 43mAir Canada
Deal found 19/2C$ 419
Tue 11/37:18 a.m.SEA - YYZ
Nonstop4h 37mAlaska Airlines
Wed 19/34:20 p.m.YYZ - SEA
Nonstop5h 20mAlaska Airlines
Deal found 18/2C$ 429
Wed 19/35:00 a.m.SEA - YYZ
1 stop16h 22mUnited Airlines
Sun 23/37:05 p.m.YYZ - SEA
Nonstop5h 25mUnited Airlines
Deal found 19/2C$ 453
Tue 11/310:55 p.m.SEA - YYZ
1 stop7h 27mDelta
Tue 25/31:20 p.m.YYZ - SEA
1 stop8h 39mDelta
Deal found 18/2C$ 464
Thu 3/49:48 a.m.SEA - YTZ
3 stops30h 05mMultiple Airlines
Sun 6/410:40 a.m.YTZ - SEA
3 stops25h 03mMultiple Airlines
Deal found 20/2C$ 494

Find flights from Seattle to Ontario within your budget

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 21 February 2025.

Fly from

Seattle

Fly to

Ontario

Route

Depart

Return

Price

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Wed 2/4

9:48 a.m.-6:43 a.m.

1 stop17h 55m

Toronto Pearson Intl

Tue 8/4

8:00 p.m.-11:35 a.m.

1 stop18h 35m

C$ 293

SeattleToronto

SEA - YKF

SEAYKF

Seattle/Tacoma Intl

Mon 7/4

3:15 p.m.-1:16 a.m.

1 stop7h 01m

Toronto Region of Waterloo Intl

Tue 8/4

6:30 a.m.-2:21 p.m.

1 stop10h 51m

C$ 341

SeattleOttawa

SEA - YOW

SEAYOW

Seattle/Tacoma Intl

Tue 11/3

11:48 a.m.-4:45 p.m.

1 stop25h 57m

Ottawa

Mon 17/3

6:10 p.m.-11:46 a.m.

1 stop20h 36m

C$ 375

SeattleToronto

SEA - YKF

SEAYKF

Seattle/Tacoma Intl

Sun 6/4

11:30 a.m.-1:16 a.m.

2 stops10h 46m

Toronto Region of Waterloo Intl

Sun 13/4

9:05 p.m.-2:21 p.m.

1 stop20h 16m

C$ 388

SeattleHamilton

SEA - YHM

SEAYHM

Seattle/Tacoma Intl

Wed 28/5

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

1 stop7h 51m

Hamilton

Sun 8/6

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

1 stop9h 58m

C$ 401

SeattleToronto

SEA - YTZ

SEAYTZ

Seattle/Tacoma Intl

Sat 5/4

5:45 a.m.-8:37 p.m.

2 stops11h 52m

Toronto Island

Sat 12/4

4:20 p.m.-10:03 p.m.

2 stops8h 43m

C$ 419

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Wed 14/5

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

1 stop7h 34m

Toronto Pearson Intl

Wed 21/5

6:30 a.m.-12:58 p.m.

1 stop9h 28m

C$ 430

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Thu 13/3

7:18 a.m.-2:55 p.m.

Nonstop4h 37m

Toronto Pearson Intl

Tue 18/3

4:20 p.m.-6:44 p.m.

Nonstop5h 24m

C$ 439

SeattleMontreal

SEA - YUL

SEAYUL

Seattle/Tacoma Intl

Tue 11/3

12:41 p.m.-12:39 a.m.

2 stops32h 58m

Montreal Pierre Elliott Trudeau Intl

Mon 17/3

3:55 p.m.-7:02 p.m.

3 stops30h 07m

C$ 447

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Wed 19/3

5:00 a.m.-12:22 a.m.

1 stop16h 22m

Toronto Pearson Intl

Sun 23/3

7:05 p.m.-9:30 p.m.

Nonstop5h 25m

C$ 453

Flights are sorted by cheapest round-trip flights first.

Deals found on 20/2

Showing 1-10 of 57 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.

Travel insights for flights from Seattle to Ontario

Get recent, data-driven insights about flights from Seattle to Ontario including ideal travel times, pricing trends, and more.

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 21 February 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 21 February 2025.

The most flights from SEA to CAON are scheduled on a Wednesday (5 on average). You will have fewer flight options on Tuesday, 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 21 February 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
9,697 reviews
Check prices

Entertainment

7.1

Boarding

8.2

Overall

8.0

Comfort

7.9

Food

7.1

Crew

8.5

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
9,697 reviews
Alaska Airlines
8.0
Very good
9,697 reviews
Check prices

Entertainment

7.1

Boarding

8.2

Overall

8.0

Comfort

7.9

Food

7.1

Crew

8.5

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
8,219 reviews
Alaska Airlines
8.0
Very good
9,697 reviews
Check prices

Entertainment

7.1

Boarding

8.2

Overall

8.0

Comfort

7.9

Food

7.1

Crew

8.5

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
8,765 reviews
Alaska Airlines
8.0
Very good
9,697 reviews
Check prices

Entertainment

7.1

Boarding

8.2

Overall

8.0

Comfort

7.9

Food

7.1

Crew

8.5

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
9,697 reviews
Check prices

Entertainment

7.1

Boarding

8.2

Overall

8.0

Comfort

7.9

Food

7.1

Crew

8.5

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
2,801 reviews
Alaska Airlines
8.0
Very good
9,697 reviews
Check prices

Entertainment

7.1

Boarding

8.2

Overall

8.0

Comfort

7.9

Food

7.1

Crew

8.5

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 Alaska Airlines (C$ 180), WestJet (C$ 188), and Delta (C$ 193).

  • 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 Qatar Airways (89%), Alaska Airlines (89%) or Hawaiian Airlines (89%) 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$ 139. On average you can expect to pay C$ 599. The most popular route, (Seattle/Tacoma Intl - Toronto Pearson Intl), can usually be booked for C$ 357.

  • 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.

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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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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 21 February 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 231AverageC$ 837FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
Alaska AirlinesCheapestC$ 379AverageC$ 683FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
United AirlinesCheapestC$ 493AverageC$ 825FlexibilityNo cancel feeOn-time69%
Search United Airlines flights

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

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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?

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