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Cheap flights from Seattle to Ontario from $103

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Ontario departing on 2/22. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Seattle to Ontario

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
11:55 am - 11:38 pm
SEA
-
YYZ
8h 43m2 stops
Multiple Airlines Logo
4:45 pm - 7:18 pm
YYZ
-
SEA
5h 33mnonstop
$245Multiple Airlines
Fri, Feb 27 - Fri, Mar 6
WestJet Logo
7:05 am - 6:52 pm
SEA
-
YYZ
8h 47m1 stop
WestJet Logo
6:30 am - 1:08 pm
YYZ
-
SEA
9h 38m1 stop
$246WestJet
Mon, May 25 - Fri, May 29
Alaska Airlines Logo
7:55 am - 3:35 pm
SEA
-
YYZ
4h 40mnonstop
Alaska Airlines Logo
4:45 pm - 7:18 pm
YYZ
-
SEA
5h 33mnonstop
$247Alaska Airlines
Sun, Feb 22 - Mon, Mar 2
WestJet Logo
3:10 pm - 5:58 am
SEA
-
YYZ
11h 48m2 stops
WestJet Logo
12:00 pm - 8:28 pm
YYZ
-
SEA
11h 28m2 stops
$248WestJet
Fri, Apr 24 - Wed, Apr 29
WestJet Logo
3:35 pm - 5:50 am
SEA
-
YYZ
11h 15m2 stops
WestJet Logo
12:00 pm - 8:28 pm
YYZ
-
SEA
11h 28m2 stops
$249WestJet
Sun, Apr 26 - Fri, May 1
WestJet Logo
2:05 pm - 12:42 am
SEA
-
YUL
7h 37m1 stop
WestJet Logo
6:45 am - 1:08 pm
YUL
-
SEA
9h 23m1 stop
$249WestJet
Sun, Apr 26 - Wed, Apr 29
Air Canada Logo
8:10 am - 3:53 pm
SEA
-
YYZ
4h 43mnonstop
Air Canada Logo
7:50 pm - 10:16 pm
YYZ
-
SEA
5h 26mnonstop
$252Air Canada
Wed, Feb 18 - Wed, Feb 18
Air Canada Logo
8:00 pm - 8:46 am
SEA
-
YXU
9h 46m2 stops
Air Canada Logo
5:40 pm - 10:16 pm
YXU
-
SEA
7h 36m1 stop
$283Air Canada
Thu, Jan 22 - Mon, Jan 26
United Airlines Logo
12:35 pm - 5:05 pm
SEA
-
YXU
25h 30m3 stops
United Airlines Logo
5:10 am - 10:43 pm
YXU
-
SEA
20h 33m2 stops
$394United Airlines
Fri, Jan 30 - Fri, Feb 6
United Airlines Logo
12:57 pm - 5:05 pm
SEA
-
YXU
25h 08m3 stops
United Airlines Logo
9:25 am - 10:43 pm
YXU
-
SEA
16h 18m3 stops
$400United Airlines
Fri, Jan 30 - Fri, Feb 6

WestJet flights from Seattle to Region of Ontario

Our best WestJet deals on Seattle to Region of Ontario flight tickets
WestJet
May 25
SEA7:05 amSeattle/Tacoma Intl
8h 47m
1 stop
YYZ6:52 pmToronto Pearson Intl
May 29
YYZ6:30 amToronto Pearson Intl
9h 38m
1 stop
SEA1:08 pmSeattle/Tacoma Intl
$246
Find similar
WestJet
Apr 24
SEA3:10 pmSeattle/Tacoma Intl
11h 48m
2 stops
YYZ5:58 amToronto Pearson Intl
Apr 29
YYZ12:00 pmToronto Pearson Intl
11h 28m
2 stops
SEA8:28 pmSeattle/Tacoma Intl
$248
Find similar
WestJet
Apr 26
SEA3:35 pmSeattle/Tacoma Intl
11h 15m
2 stops
YYZ5:50 amToronto Pearson Intl
May 1
YYZ12:00 pmToronto Pearson Intl
11h 28m
2 stops
SEA8:28 pmSeattle/Tacoma Intl
$249
Find similar

Alaska Airlines flights from Seattle to Region of Ontario

Our best Alaska Airlines deals on Seattle to Region of Ontario flight tickets
Alaska Airlines
Feb 22
SEA7:55 amSeattle/Tacoma Intl
4h 40m
YYZ3:35 pmToronto Pearson Intl
Mar 6
YYZ4:45 pmToronto Pearson Intl
5h 33m
SEA7:18 pmSeattle/Tacoma Intl
$247
Find similar
Alaska Airlines
Apr 25
SEA7:55 amSeattle/Tacoma Intl
4h 40m
YYZ3:35 pmToronto Pearson Intl
Apr 29
YYZ4:45 pmToronto Pearson Intl
5h 20m
SEA7:05 pmSeattle/Tacoma Intl
$296
Find similar
Alaska Airlines
Dec 27
SEA8:00 amSeattle/Tacoma Intl
4h 35m
YYZ3:35 pmToronto Pearson Intl
Jan 6
YYZ4:45 pmToronto Pearson Intl
5h 26m
SEA7:11 pmSeattle/Tacoma Intl
$720
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to Region of 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, momondo users made 832,500 searches. Data last updated December 18, 2025.
Use the filters below to find and compare flights from Seattle to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Fri 2/27

11:55 am-11:38 pm

2 stops8h 43m

Toronto Pearson Intl

Fri 3/6

4:45 pm-7:18 pm

Nonstop5h 33m

$245

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Mon 5/25

7:05 am-6:52 pm

1 stop8h 47m

Toronto Pearson Intl

Fri 5/29

6:30 am-1:08 pm

1 stop9h 38m

$246

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Sun 2/22

7:55 am-3:35 pm

Nonstop4h 40m

Toronto Pearson Intl

Mon 3/2

4:45 pm-7:18 pm

Nonstop5h 33m

$247

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Fri 4/24

3:10 pm-5:58 am

2 stops11h 48m

Toronto Pearson Intl

Wed 4/29

12:00 pm-8:28 pm

2 stops11h 28m

$248

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Sun 4/26

3:35 pm-5:50 am

2 stops11h 15m

Toronto Pearson Intl

Fri 5/1

12:00 pm-8:28 pm

2 stops11h 28m

$249

SeattleMontreal

SEA - YUL

SEAYUL

Seattle/Tacoma Intl

Sun 4/26

2:05 pm-12:42 am

1 stop7h 37m

Montreal Pierre Elliott Trudeau Intl

Wed 4/29

6:45 am-1:08 pm

1 stop9h 23m

$249

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

Wed 2/18

8:10 am-3:53 pm

Nonstop4h 43m

Toronto Pearson Intl

Wed 2/18

7:50 pm-10:16 pm

Nonstop5h 26m

$252

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Thu 1/22

8:00 pm-8:46 am

2 stops9h 46m

London

Mon 1/26

5:40 pm-10:16 pm

1 stop7h 36m

$283

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 1/30

12:35 pm-5:05 pm

3 stops25h 30m

London

Fri 2/6

5:10 am-10:43 pm

2 stops20h 33m

$394

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

Fri 1/30

12:57 pm-5:05 pm

3 stops25h 08m

London

Fri 2/6

9:25 am-10:43 pm

3 stops16h 18m

$400

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Ontario from

How to get the cheapest flight ticket from Seattle to Region of Ontario

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Region of Ontario?

The month of November is, on average, the cheapest month to fly to Region of Ontario from Seattle, with most prices found around $274. If you aren’t able to travel during the month of November, then book flights to Region of Ontario from Seattle during January instead. Flights to Region of Ontario in January, while not as cheap as those in November, still average around $283.

What is the cheapest day to depart on your flight to Region of Ontario?

According to our data, Tuesday is the cheapest day to fly to Region of Ontario from Seattle. The lowest ticket price found for a Tuesday departure recently was $539. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. Flights from Seattle to Region of Ontario on a Saturday will generally be more expensive and average around $712. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

What is the cheapest time of day to depart on your flight to Region of Ontario?

According to our data, the cheapest time of day to fly to Region of Ontario is in the afternoon. momondo users have found flights departing from Seattle to Region of Ontario in the afternoon for as low as $283. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the morning are often more expensive with an average ticket price of $615.

What is the cheapest Seattle/Tacoma Intl to Ontario flight route?

Fly from Seattle/Tacoma Intl to Toronto Pearson Intl for the best Seattle/Tacoma Intl - Ontario flight prices

How far in advance should I book a flight to Region of Ontario?

You are more likely to see cheaper flights to Region of Ontario from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Region of Ontario for around $413 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Region of Ontario from Seattle for as low as $292 on momondo.

What cabin class options are available on Seattle/Tacoma Intl to Ontario flights?

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to Ontario flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Seattle to Region of Ontario flights?

No. A direct flight is the cheapest option for a flight between Seattle to Region of Ontario.

Cheap Seattle to Region of Ontario flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to Region of Ontario

Best Price Found

$154

Fastest flight time

4h 35m

Direct flights

Every day

Airports in Region of Ontario

123 airports
The best one-way flight to Region of Ontario from Seattle in the past 72 hours is $154. The best round-trip flight deal from Seattle to Region of Ontario found on momondo in the last 72 hours is $382.
The fastest flight from Seattle to Region of Ontario takes 4h 35m
Direct flights go from Seattle to Region of Ontario every day.
There are 123 airports in Region of Ontario. From Seattle there are direct flights to Montreal Pierre Elliott Trudeau Intl (YUL), Toronto Pearson Intl (YYZ).
Search flight deals

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Ontario?

    Prices for flights from Seattle/Tacoma Intl Airport to Ontario are refreshed on a daily basis.

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Ontario?

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to Ontario?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Seattle/Tacoma Intl Airport to Ontario.

  • What documentation or ID do you need to fly to Ontario?

    The travel and health documents you'll need for your trip to Ontario may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Ontario. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Seattle to Region of Ontario?

Best airlines flying from Seattle to Region of Ontario

Compare and see reviews for airlines that fly from Seattle to Region of Ontario with momondo
Airline
Rating
Free Cancellation
Price
Air CanadaPriceFrom $151Free CancellationRating
7.1
10,534 reviews
Search Air Canada flights
United AirlinesPriceFrom $173Free CancellationRating
7.4
9,090 reviews
Search United Airlines flights
DeltaPriceFrom $182Free CancellationRating
7.9
8,006 reviews
Search Delta flights
WestJetPriceFrom $226Free CancellationRating
7.2
3,203 reviews
Search WestJet flights
Alaska AirlinesPriceFrom $253Free CancellationRating
8.0
11,476 reviews
Search Alaska Airlines flights

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to Ontario?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Seattle to Ontario. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Seattle to Ontario with flexible booking policies on momondo?

Yes. All flights to Ontario from Seattle on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Seattle to Ontario?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Ontario from Seattle.

I’m not ready to book a flight from Seattle to Ontario right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of Seattle to Ontario flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

An easier way to manage your Region of Ontario trip

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