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Cheap flights from Seattle to Ontario from $100

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 2/18. 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.
Air Canada Logo
8:00 am - 3:43 pm
SEA
-
YYZ
4h 43mnonstop
Air Canada Logo
8:00 am - 3:01 pm
YYZ
-
SEA
10h 01m
2 stops
$225Air Canada
sáb., feb. 28 - sáb., mar. 7
Air Canada Logo
8:00 am - 3:43 pm
SEA
-
YYZ
4h 43mnonstop
Air Canada Logo
8:00 am - 2:31 pm
YYZ
-
SEA
9h 31m
1 stop
$227Air Canada
sáb., feb. 21 - sáb., feb. 28
Multiple Airlines Logo
8:00 am - 3:43 pm
SEA
-
YYZ
4h 43mnonstop
Multiple Airlines Logo
4:45 pm - 7:18 pm
YYZ
-
SEA
5h 33mnonstop
$233Multiple Airlines
sáb., feb. 21 - sáb., feb. 28
Multiple Airlines Logo
3:20 pm - 5:58 am
SEA
-
YYZ
11h 38m
2 stops
Multiple Airlines Logo
5:55 pm - 10:57 pm
YYZ
-
SEA
8h 02m
1 stop
$234Multiple Airlines
sáb., feb. 21 - sáb., feb. 28
Multiple Airlines Logo
7:55 am - 3:35 pm
SEA
-
YYZ
4h 40mnonstop
Multiple Airlines Logo
7:45 am - 2:19 pm
YYZ
-
SEA
9h 34m
1 stop
$235Multiple Airlines
mar., mar. 17 - mar., abr. 7
Air Canada Logo
8:00 am - 3:43 pm
SEA
-
YYZ
4h 43mnonstop
Air Canada Logo
8:00 am - 7:16 pm
YYZ
-
SEA
14h 16m
2 stops
$236Air Canada
mié., feb. 25 - mié., mar. 4
WestJet Logo
3:10 pm - 5:29 am
SEA
-
YKF
11h 19m
1 stop
WestJet Logo
8:40 pm - 9:40 am
YKF
-
SEA
16h 00m
1 stop
$278WestJet
mié., abr. 22 - lun., abr. 27
WestJet Logo
7:35 pm - 7:00 am
SEA
-
YUL
8h 25m
1 stop
WestJet Logo
5:30 pm - 9:40 am
YUL
-
SEA
19h 10m
1 stop
$284WestJet
dom., may. 17 - mié., may. 20
United Airlines Logo
5:00 am - 5:05 pm
SEA
-
YXU
9h 05m
2 stops
United Airlines Logo
5:10 am - 10:43 pm
YXU
-
SEA
20h 33m
2 stops
$436United Airlines
mié., feb. 11 - dom., feb. 15
United Airlines Logo
9:20 am - 5:05 pm
SEA
-
YXU
28h 45m
2 stops
United Airlines Logo
5:10 am - 6:30 pm
YXU
-
SEA
16h 20m
2 stops
$777United Airlines
sáb., mar. 14 - sáb., mar. 21

WestJet flights from Seattle to Region of Ontario

Our best WestJet deals on Seattle to Region of Ontario flight tickets
WestJet
May 23
SEA7:35 pmSeattle/Tacoma Intl
8h 20m
1 stop
YYZ6:55 amToronto Pearson Intl
Jun 4
YYZ1:30 pmToronto Pearson Intl
8h 15m
1 stop
SEA6:45 pmSeattle/Tacoma Intl
$240
WestJet
May 2
SEA7:35 pmSeattle/Tacoma Intl
7h 10m
1 stop
YYZ5:45 amToronto Pearson Intl
May 9
YYZ1:30 pmToronto Pearson Intl
8h 15m
1 stop
SEA6:45 pmSeattle/Tacoma Intl
$242
WestJet
May 20
SEA7:35 pmSeattle/Tacoma Intl
8h 20m
1 stop
YYZ6:55 amToronto Pearson Intl
Jun 4
YYZ1:30 pmToronto Pearson Intl
8h 15m
1 stop
SEA6:45 pmSeattle/Tacoma Intl
$247

United Airlines flights from Seattle to Region of Ontario

Our best United Airlines deals on Seattle to Region of Ontario flight tickets
United Airlines
Mar 3
SEA5:20 pmSeattle/Tacoma Intl
11h 10m
1 stop
YYZ7:30 amToronto Pearson Intl
Mar 4
YYZ10:51 amToronto Pearson Intl
11h 12m
1 stop
SEA7:03 pmSeattle/Tacoma Intl
$264
United Airlines
Mar 17
SEA11:59 pmSeattle/Tacoma Intl
6h 59m
1 stop
YYZ9:58 amToronto Pearson Intl
Apr 7
YYZ3:00 pmToronto Pearson Intl
11h 46m
1 stop
SEA11:46 pmSeattle/Tacoma Intl
$288
United Airlines
Feb 11
SEA5:00 amSeattle/Tacoma Intl
9h 05m
2 stops
YXU5:05 pmLondon
Feb 15
YXU5:10 amLondon
20h 33m
2 stops
SEA10:43 pmSeattle/Tacoma Intl
$436

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 enero 29, 2026.
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

sáb. 2/28

8:00 am-3:43 pm

Nonstop4h 43m

Toronto Pearson Intl

sáb. 3/7

8:00 am-3:01 pm

2 stops10h 01m

$225

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

sáb. 2/21

8:00 am-3:43 pm

Nonstop4h 43m

Toronto Pearson Intl

sáb. 2/28

8:00 am-2:31 pm

1 stop9h 31m

$227

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

sáb. 2/21

8:00 am-3:43 pm

Nonstop4h 43m

Toronto Pearson Intl

sáb. 2/28

4:45 pm-7:18 pm

Nonstop5h 33m

$233

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

sáb. 2/21

3:20 pm-5:58 am

2 stops11h 38m

Toronto Pearson Intl

sáb. 2/28

5:55 pm-10:57 pm

1 stop8h 02m

$234

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

mar. 3/17

7:55 am-3:35 pm

Nonstop4h 40m

Toronto Pearson Intl

mar. 4/7

7:45 am-2:19 pm

1 stop9h 34m

$235

SeattleToronto

SEA - YYZ

SEAYYZ

Seattle/Tacoma Intl

mié. 2/25

8:00 am-3:43 pm

Nonstop4h 43m

Toronto Pearson Intl

mié. 3/4

8:00 am-7:16 pm

2 stops14h 16m

$236

SeattleToronto

SEA - YKF

SEAYKF

Seattle/Tacoma Intl

mié. 4/22

3:10 pm-5:29 am

1 stop11h 19m

Toronto Region of Waterloo Intl

lun. 4/27

8:40 pm-9:40 am

1 stop16h 00m

$278

SeattleMontreal

SEA - YUL

SEAYUL

Seattle/Tacoma Intl

dom. 5/17

7:35 pm-7:00 am

1 stop8h 25m

Montreal Pierre Elliott Trudeau Intl

mié. 5/20

5:30 pm-9:40 am

1 stop19h 10m

$284

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

mié. 2/11

5:00 am-5:05 pm

2 stops9h 05m

London

dom. 2/15

5:10 am-10:43 pm

2 stops20h 33m

$436

SeattleLondon

SEA - YXU

SEAYXU

Seattle/Tacoma Intl

sáb. 3/14

9:20 am-5:05 pm

2 stops28h 45m

London

sáb. 3/21

5:10 am-6:30 pm

2 stops16h 20m

$777

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 January is, on average, the cheapest month to fly to Region of Ontario from Seattle, with most prices found around $269. If you aren’t able to travel during the month of January, then book flights to Region of Ontario from Seattle during November instead. Flights to Region of Ontario in November, while not as cheap as those in January, still average around $274.

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 $513. 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 $706. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

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 $389 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 $204 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

$99

Fastest flight time

4h 40m

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 $99. The best round-trip flight deal from Seattle to Region of Ontario found on momondo in the last 72 hours is $342.
The fastest flight from Seattle to Region of Ontario takes 4h 40m
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
United AirlinesPriceFrom $124Free CancellationRating
7.4
9,215 reviews
Search United Airlines flights
Air CanadaPriceFrom $132Free CancellationRating
7.1
10,667 reviews
Search Air Canada flights
DeltaPriceFrom $165Free CancellationRating
7.9
8,127 reviews
Search Delta flights
WestJetPriceFrom $226Free CancellationRating
7.2
3,253 reviews
Search WestJet flights
Alaska AirlinesPriceFrom $252Free CancellationRating
8.0
11,807 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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