Cheap flights from Ontario to Seattle from C$ 170
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 15/7. Fares are subject to change and may not be available on all flights or dates of travel.
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 2 July 2025.
Round-trip from | C$ 267 |
---|---|
One-way from | C$ 170 |
Popular in | July |
Cheapest in | February |
Average price | C$ 587 |
Good round-trip deal | C$ 576 or less |
Good one-way deal | C$ 267 or less |
Find flight deals from Ontario to Seattle
Cheapest flights from Ontario to SeattleExplore 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 2 July 2025.
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 2 July 2025.
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 2 July 2025.
Use the filters below to find and compare flights from Ontario to Seattle that are best for you.
Fly from
Fly to
Route
Depart
Return
Price
HamiltonSeattle
YHM - SEA
YHMSEA
Hamilton
Mon 18/8
6:00 a.m.-12:58 p.m.
1 stop9h 58m
Seattle/Tacoma Intl
Mon 25/8
2:05 p.m.-12:41 a.m.
1 stop7h 36m
LondonSeattle
YXU - SEA
YXUSEA
London
Thu 14/8
8:00 p.m.-8:28 p.m.
1 stop27h 28m
Seattle/Tacoma Intl
Thu 21/8
7:35 p.m.-5:14 a.m.
1 stop6h 39m
LondonSeattle
YXU - SEA
YXUSEA
London
Thu 14/8
9:55 a.m.-8:41 p.m.
2 stops13h 46m
Seattle/Tacoma Intl
Thu 21/8
7:35 p.m.-5:14 a.m.
1 stop6h 39m
TorontoSeattle
YKF - SEA
YKFSEA
Toronto Region of Waterloo Intl
Fri 15/8
6:00 a.m.-8:28 p.m.
1 stop17h 28m
Seattle/Tacoma Intl
Fri 22/8
1:50 p.m.-12:46 a.m.
1 stop7h 56m
TorontoSeattle
YYZ - SEA
YYZSEA
Toronto Pearson Intl
Fri 25/7
3:00 p.m.-8:28 p.m.
1 stop8h 28m
Seattle/Tacoma Intl
Sat 2/8
7:35 p.m.-6:12 a.m.
1 stop7h 37m
TorontoSeattle
YTZ - SEA
YTZSEA
Toronto Island
Mon 6/10
12:25 p.m.-7:31 p.m.
1 stop10h 06m
Seattle/Tacoma Intl
Sun 12/10
7:15 p.m.-11:45 a.m.
2 stops13h 30m
TorontoSeattle
YYZ - SEA
YYZSEA
Toronto Pearson Intl
Fri 18/7
12:45 p.m.-12:56 a.m.
1 stop15h 11m
Seattle/Tacoma Intl
Fri 7/11
6:20 a.m.-5:54 p.m.
1 stop8h 34m
TorontoSeattle
YYZ - SEA
YYZSEA
Toronto Pearson Intl
Mon 6/10
10:00 a.m.-7:31 p.m.
2 stops12h 31m
Seattle/Tacoma Intl
Mon 13/10
7:15 a.m.-6:34 p.m.
1 stop8h 19m
TorontoSeattle
YYZ - SEA
YYZSEA
Toronto Pearson Intl
Thu 4/12
6:15 a.m.-2:43 p.m.
2 stops11h 28m
Seattle/Tacoma Intl
Sat 10/1
11:54 a.m.-11:00 p.m.
1 stop8h 06m
WindsorSeattle
YQG - SEA
YQGSEA
Windsor
Tue 29/7
7:45 p.m.-6:38 p.m.
1 stop25h 53m
Seattle/Tacoma Intl
Thu 31/7
7:05 a.m.-6:55 p.m.
1 stop8h 50m
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.
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$ 262). 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 2 July 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 2 July 2025.
The most flights from CAON to SEA are scheduled on a Tuesday (6 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (2 on average).
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 2 July 2025.
Check out reviews from past customers who have flown with Alaska Airlines,Delta, andUnited Airlines from Ontario to Seattle to help guide your decision. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Boarding
Overall
Comfort
Crew
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Boarding
Overall
Comfort
Crew
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Boarding
Overall
Comfort
Crew
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Boarding
Overall
Comfort
Crew
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Boarding
Overall
Comfort
Crew
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Boarding
Overall
Comfort
Crew
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
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.
Travelling to a place near Ontario?
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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.
Top 6 airlines flying from Ontario to Seattle
Discover the top 6 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 2 July 2025.
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How does Cheapflights help users find flights from Ontario to Seattle?
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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?
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