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Ontario

$131+ Cheap flights from Seattle (SEA) to Ontario

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 4/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YYZ
Mar 30 — Apr 61
Sun 3/30
Sun 4/6
1 adult, Economy
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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 March 25, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$232
(Mytrip)

One-way from

$131
(Mytrip)

Popular in

April

Cheapest in

January

Average price

$369

Good round-trip deal

$468 or less

Good one-way deal

$223 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-Toronto (YTO) flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Toronto (YTO) flights.
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From Seattle/Tacoma Intl to Ontario
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One-way flight from Seattle/Tacoma Intl to Ontario
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Highest demand for flights based on searches. 9% potential increase in price ($43 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($11 potential savings vs. average RT price).
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Average for round-trip flights in March 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 March 25, 2025.

This Mytrip deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/1612:30 pmSEA - YYZ
1 stop15h 13mMultiple Airlines
Wed 4/3012:00 pmYYZ - SEA
2 stops34h 51mMultiple Airlines
Deal found 3/23$232
This Trip.com deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/151:50 pmSEA - YKF
1 stop12h 25mMultiple Airlines
Mon 5/196:00 amYKF - SEA
1 stop9h 58mMultiple Airlines
Deal found 3/24$270
This Mytrip deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/612:30 pmSEA - YHM
2 stops33h 11mMultiple Airlines
Mon 5/126:00 amYHM - SEA
2 stops35h 25mMultiple Airlines
Deal found 3/23$285
This Flightnetwork deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/75:40 amSEA - YTZ
2 stops11h 57mAir Canada
Wed 5/1410:20 amYTZ - SEA
2 stops12h 17mAir Canada
Deal found 3/23$285
This Trip.com deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/52:05 pmSEA - YKF
1 stop7h 41mWestJet
Tue 5/66:00 amYKF - SEA
1 stop9h 58mWestJet
Deal found 3/24$287
This Trip.com deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/317:05 amSEA - YOW
1 stop8h 16mWestJet
Sun 8/106:10 amYOW - SEA
1 stop9h 21mWestJet
Deal found 3/24$294
This Kiwi.com deal was found by Cheapflights users on 3/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/57:35 pmSEA - YYZ
1 stop8h 17mWestJet
Fri 7/116:45 amYYZ - SEA
1 stop8h 46mWestJet
Deal found 3/22$295
This Trip.com deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/271:50 pmSEA - YHM
1 stop7h 51mWestJet
Mon 6/306:00 amYHM - SEA
1 stop9h 58mWestJet
Deal found 3/23$295
This Flightnetwork deal was found by Cheapflights users on 3/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/711:40 amSEA - YYZ
Nonstop4h 57mAir Canada
Wed 5/148:30 amYYZ - SEA
Nonstop5h 21mAir Canada
Deal found 3/22$320
This Mytrip deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/73:20 pmSEA - YTZ
3 stops17h 12mMultiple Airlines
Wed 5/1410:20 amYTZ - SEA
2 stops12h 17mMultiple Airlines
Deal found 3/23$322
This Trip.com deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/67:05 amSEA - YOW
2 stops10h 56mMultiple Airlines
Tue 5/133:35 pmYOW - SEA
1 stop7h 53mMultiple Airlines
Deal found 3/24$324
This Justfly.com deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/142:05 pmSEA - YUL
1 stop7h 38mWestJet
Tue 7/227:00 amYUL - SEA
1 stop8h 58mWestJet
Deal found 3/23$325

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 2,558,603 searches. Data last updated March 25, 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

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Wed 4/16

12:30 pm-6:43 am

1 stop15h 13m

Toronto Pearson Intl

Wed 4/30

12:00 pm-7:51 pm

2 stops34h 51m

$232

SeattleToronto

SEA - YKF

SEAYKF

Seattle/Tacoma Intl

Thu 5/15

1:50 pm-5:15 am

1 stop12h 25m

Toronto Region of Waterloo Intl

Mon 5/19

6:00 am-12:58 pm

1 stop9h 58m

$270

SeattleToronto

SEA - YTZ

SEAYTZ

Seattle/Tacoma Intl

Wed 5/7

5:40 am-8:37 pm

2 stops11h 57m

Toronto Island

Wed 5/14

10:20 am-7:37 pm

2 stops12h 17m

$285

SeattleHamilton

SEA - YHM

SEAYHM

Seattle/Tacoma Intl

Tue 5/6

12:30 pm-12:41 am

2 stops33h 11m

Hamilton

Mon 5/12

6:00 am-2:25 pm

2 stops35h 25m

$285

SeattleToronto

SEA - YKF

SEAYKF

Seattle/Tacoma Intl

Mon 5/5

2:05 pm-12:46 am

1 stop7h 41m

Toronto Region of Waterloo Intl

Tue 5/6

6:00 am-12:58 pm

1 stop9h 58m

$287

SeattleOttawa

SEA - YOW

SEAYOW

Seattle/Tacoma Intl

Thu 7/31

7:05 am-6:21 pm

1 stop8h 16m

Ottawa

Sun 8/10

6:10 am-12:31 pm

1 stop9h 21m

$294

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Sat 7/5

7:35 pm-6:52 am

1 stop8h 17m

Toronto Pearson Intl

Fri 7/11

6:45 am-12:31 pm

1 stop8h 46m

$295

SeattleHamilton

SEA - YHM

SEAYHM

Seattle/Tacoma Intl

Fri 6/27

1:50 pm-12:41 am

1 stop7h 51m

Hamilton

Mon 6/30

6:00 am-12:58 pm

1 stop9h 58m

$295

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Wed 5/7

11:40 am-7:37 pm

Nonstop4h 57m

Toronto Pearson Intl

Wed 5/14

8:30 am-10:51 am

Nonstop5h 21m

$320

SeattleToronto

SEA - YTZ

SEAYTZ

Seattle/Tacoma Intl

Wed 5/7

3:20 pm-11:32 am

3 stops17h 12m

Toronto Island

Wed 5/14

10:20 am-7:37 pm

2 stops12h 17m

$322

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/23

Showing 1-10 of 59 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 $243). Flying from Seattle to Region of Ontario in July is currently the most expensive (average of $359). 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 March 25, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to Region of Ontario as you normally would.

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 2.0 - 3.3 inches per month. June is typically the wettest month, when rainfall can reach 3.3 in. February is typically the driest time to visit Region of Ontario when rainfall is around 2.0 in.

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 69.8 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 21.2 F).

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 March 25, 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
9,782 reviews

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Food

7.1

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
9,782 reviews
Alaska Airlines
8.0
Very good
9,782 reviews

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Food

7.1

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
7,890 reviews
Alaska Airlines
8.0
Very good
9,782 reviews

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Food

7.1

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
8,605 reviews
Alaska Airlines
8.0
Very good
9,782 reviews

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Food

7.1

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
9,782 reviews

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Food

7.1

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
2,785 reviews
Alaska Airlines
8.0
Very good
9,782 reviews

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Food

7.1

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?

    For a flight from Seattle to Ontario, you will be flying from Seattle/Tacoma Intl. Seattle/Tacoma Intl (SEA) is just 11.4 mi from the center of the city.

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

    To fly one-way, consider booking your trip with WestJet, which is currently one of the cheapest options available, starting at $137. Delta flights start at $153 while deals on Air Canada start at $153 one-way.

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

    The most popular route from Seattle to Region of Ontario is Seattle/Tacoma Intl - Toronto Pearson Intl. You may also consider Seattle/Tacoma Intl - Montreal Pierre Elliott Trudeau Intl or Seattle/Tacoma Intl - Toronto Region of Waterloo Intl.

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

    The top 3 most reliable airlines when flying from Seattle to Region of Ontario are Air Tahiti Nui (100%), Alaska Airlines (90%) and Hawaiian Airlines (90%).

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

    Looking for the cheapest flight from Seattle to Region of Ontario? While on average our users pay $717, our data indicates the cheapest price to be $160. The most popular route (Seattle/Tacoma Intl - Toronto Pearson Intl), is priced around $257.

  • 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 $243). Flying from Seattle to Region of Ontario in July is currently the most expensive (average of $359). 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 Kelowna flights
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Portland to Whitehorse flights
Spokane to Hamilton flights
Pasco to Pearson Intl flights
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Top 5 airlines flying from Seattle to Ontario

Discover the top 5 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 2,558,603 searches. Data last updated March 25, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$138Average$488FlexibilityNo cancel feeOn-time67%
United AirlinesCheapest$158Average$528FlexibilityNo cancel feeOn-time69%
WestJetCheapest$235Average$482FlexibilityNo cancel feeOn-time60%
Alaska AirlinesCheapest$248Average$495FlexibilityNo cancel feeOn-time75%
DeltaCheapest$427Average$593FlexibilityNo cancel feeOn-timeN/A
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