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Cheap flights from Seattle to Los Angeles from C$ 124

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 Los Angeles departing on 28/1. 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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Find the cheapest flights from Seattle to Los Angeles

Cheap round-trip flights

Enter your travel dates to find the best prices.
Delta Logo
8:17 a.m. - 11:08 a.m.SEA-ONT
2h 51mdirect
Delta Logo
6:45 a.m. - 9:49 a.m.ONT-SEA
3h 04mdirect
C$ 247Delta
Find Deal
Wed, 19 Nov - Wed, 26 Nov
Alaska Airlines Logo
3:57 p.m. - 6:33 p.m.SEA-ONT
2h 36mdirect
Alaska Airlines Logo
6:00 a.m. - 8:57 a.m.ONT-SEA
2h 57mdirect
C$ 261Alaska Airlines
Find Deal
Sat, 6 Dec - Sun, 7 Dec
Frontier Logo
6:18 p.m. - 2:04 p.m.SEA-ONT
19h 46m1 stop
Frontier Logo
6:17 p.m. - 1:51 p.m.ONT-SEA
19h 34m1 stop
C$ 286Frontier
Find Deal
Sun, 14 Dec - Tue, 23 Dec
Southwest Logo
7:55 a.m. - 12:15 p.m.SEA-ONT
4h 20m1 stop
Southwest Logo
10:30 a.m. - 6:50 p.m.ONT-SEA
8h 20m1 stop
C$ 309Southwest
Find Deal
Thu, 19 Feb - Sun, 22 Feb
Hawaiian Airlines Logo
9:35 p.m. - 12:14 a.m.SEA-ONT
2h 39mdirect
Hawaiian Airlines Logo
4:03 p.m. - 6:54 p.m.ONT-SEA
2h 51mdirect
C$ 311Hawaiian Airlines
Find Deal
Thu, 25 Dec - Tue, 27 Jan
Frontier Logo
11:06 a.m. - 1:42 p.m.SEA-ONT
2h 36mdirect
Frontier Logo
3:50 p.m. - 6:43 p.m.ONT-SEA
2h 53mdirect
C$ 347Frontier
Find Deal
Mon, 22 Dec - Sat, 27 Dec
United Airlines Logo
5:30 a.m. - 12:37 p.m.SEA-ONT
7h 07m1 stop
United Airlines Logo
1:40 p.m. - 6:25 p.m.ONT-SEA
4h 45m1 stop
C$ 373United Airlines
Find Deal
Fri, 21 Nov - Mon, 24 Nov
United Airlines Logo
5:07 a.m. - 12:43 p.m.SEA-ONT
7h 36m1 stop
United Airlines Logo
1:45 p.m. - 11:04 p.m.ONT-SEA
9h 19m1 stop
C$ 375United Airlines
Find Deal
Thu, 5 Mar - Mon, 9 Mar
Southwest Logo
6:20 a.m. - 1:45 p.m.SEA-ONT
7h 25m2 stops
Southwest Logo
10:30 a.m. - 6:50 p.m.ONT-SEA
8h 20m1 stop
C$ 387Southwest
Find Deal
Thu, 19 Feb - Sun, 22 Feb
Hawaiian Airlines Logo
9:35 p.m. - 12:14 a.m.SEA-ONT
2h 39mdirect
Hawaiian Airlines Logo
6:00 a.m. - 8:57 a.m.ONT-SEA
2h 57mdirect
C$ 396Hawaiian Airlines
Find Deal
Mon, 29 Dec - Thu, 1 Jan

Delta flights from Seattle to Ontario

Our best Delta deals on Seattle to Ontario flight tickets
Delta
19 Nov
SEA8:17 a.m.Seattle/Tacoma Intl
2h 51m
ONT11:08 a.m.Ontario
26 Nov
ONT6:45 a.m.Ontario
3h 04m
SEA9:49 a.m.Seattle/Tacoma Intl
C$ 247
Find similar
Delta
6 Dec
SEA8:30 a.m.Seattle/Tacoma Intl
2h 43m
ONT11:13 a.m.Ontario
12 Dec
ONT6:40 a.m.Ontario
3h 05m
SEA9:45 a.m.Seattle/Tacoma Intl
C$ 261
Find similar
Delta
11 Dec
SEA8:30 a.m.Seattle/Tacoma Intl
2h 43m
ONT11:13 a.m.Ontario
14 Dec
ONT6:40 a.m.Ontario
3h 05m
SEA9:45 a.m.Seattle/Tacoma Intl
C$ 274
Find similar

Frontier flights from Seattle to Ontario

Our best Frontier deals on Seattle to Ontario flight tickets
Frontier
8 Nov
SEA7:17 p.m.Seattle/Tacoma Intl
11h 50m
1 stop
ONT7:07 a.m.Ontario
11 Nov
ONT8:45 a.m.Ontario
27h 22m
1 stop
SEA12:07 p.m.Seattle/Tacoma Intl
C$ 201
Find similar
Frontier
9 Nov
SEA11:35 a.m.Seattle/Tacoma Intl
25h 16m
1 stop
ONT12:51 p.m.Ontario
14 Nov
ONT6:00 a.m.Ontario
12h 32m
1 stop
SEA6:32 p.m.Seattle/Tacoma Intl
C$ 247
Find similar
Frontier
9 Nov
SEA11:35 a.m.Seattle/Tacoma Intl
19h 42m
1 stop
ONT7:17 a.m.Ontario
14 Nov
ONT8:02 a.m.Ontario
2h 53m
SEA10:55 a.m.Seattle/Tacoma Intl
C$ 274
Find similar

momondo 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, momondo users made 96,600 searches. Data last updated 30 October 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

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 19/11

8:17 a.m.-11:08 a.m.

Nonstop2h 51m

Ontario

Wed 26/11

6:45 a.m.-9:49 a.m.

Nonstop3h 04m

C$ 247

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 6/12

3:57 p.m.-6:33 p.m.

Nonstop2h 36m

Ontario

Sun 7/12

6:00 a.m.-8:57 a.m.

Nonstop2h 57m

C$ 261

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sun 14/12

6:18 p.m.-2:04 p.m.

1 stop19h 46m

Ontario

Tue 23/12

6:17 p.m.-1:51 p.m.

1 stop19h 34m

C$ 286

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 19/2

7:55 a.m.-12:15 p.m.

1 stop4h 20m

Ontario

Sun 22/2

10:30 a.m.-6:50 p.m.

1 stop8h 20m

C$ 309

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 25/12

9:35 p.m.-12:14 a.m.

Nonstop2h 39m

Ontario

Tue 27/1

4:03 p.m.-6:54 p.m.

Nonstop2h 51m

C$ 311

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Mon 22/12

11:06 a.m.-1:42 p.m.

Nonstop2h 36m

Ontario

Sat 27/12

3:50 p.m.-6:43 p.m.

Nonstop2h 53m

C$ 347

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Fri 21/11

5:30 a.m.-12:37 p.m.

1 stop7h 07m

Ontario

Mon 24/11

1:40 p.m.-6:25 p.m.

1 stop4h 45m

C$ 373

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 5/3

5:07 a.m.-12:43 p.m.

1 stop7h 36m

Ontario

Mon 9/3

1:45 p.m.-11:04 p.m.

1 stop9h 19m

C$ 375

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 19/2

6:20 a.m.-1:45 p.m.

2 stops7h 25m

Ontario

Sun 22/2

10:30 a.m.-6:50 p.m.

1 stop8h 20m

C$ 387

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Mon 29/12

9:35 p.m.-12:14 a.m.

Nonstop2h 39m

Ontario

Thu 1/1

6:00 a.m.-8:57 a.m.

Nonstop2h 57m

C$ 396

Flights are sorted by cheapest round-trip flights first.

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How to get the cheapest flight ticket from Seattle to 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 Ontario?

The month of March is, on average, the cheapest month to fly to Ontario from Seattle, with most prices found around C$ 262. The month of January is another great option to travel to Ontario, with average flight prices from Seattle averaging around C$ 274.

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

On average, the least expensive day to fly to Ontario from Seattle is on a Sunday. momondo users have found tickets for Sunday departures for as low as C$ 175. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Thursday is the most expensive day to depart from Seattle because it is more convenient for both business and leisure travellers. As a result, prices tend to be around C$ 332.

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

Our data shows that the cheapest Seattle to Ontario flights are usually those with departure times in the morning. Our users have found flights to Ontario in the morning for as low as C$ 216. Try not to purchase tickets at noon because they tend to be around C$ 345. Of course, these prices can vary depending on the time of year and what airport you fly to.

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

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

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

You are more likely to see cheaper flights to Ontario from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around C$ 310 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Seattle for as low as C$ 248 on momondo.

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

There is only 1 cabin class 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.

How have Seattle to Ontario flight prices changed over time?

As of October 2025, prices for Seattle to Ontario flights are approximately 2% more expensive when compared to flights at the same time last year.

When to book flights from Seattle to Ontario

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to Ontario according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to Ontario (SEA to ONT) flight deals and tips

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

Best price found

C$ 167

Fastest flight time

2h 32m

Direct flights

Every day

Airports in Ontario

1 airport
The best flight deal from Seattle to Ontario found on momondo in the last 72 hours is C$ 167
The fastest flight from Seattle to Ontario takes 2h 32m
Direct flights go from Seattle to Ontario every day.
There is 1 airport near Ontario: Ontario (ONT)
Search flight deals

  • How far is Seattle/Tacoma Intl to Ontario by plane?

    A flight from Seattle/Tacoma Intl to Ontario will travel around 1555.6 km. Flights usually cover this in 2h 32m, depending on flying conditions and air traffic around both airports.

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

    Prices for flights from Seattle/Tacoma Intl Airport to Ontario Airport refresh daily.

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

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

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Ontario Airport.

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

    The travel and health documents you'll need for your trip to Ontario Airport 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 Airport. 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 Ontario?

  • What is the most popular airline from Seattle to Ontario?

Best airlines flying from Seattle to Ontario

Compare and see reviews for airlines that fly from Seattle to Ontario with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom C$ 95Free CancellationRating
5.8
3,122 reviews
Search Frontier flights

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Ontario from Seattle.

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

momondo does allow users to show only those flights to Ontario from Seattle which offer a flexible booking policy as well as other useful filters and features.

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

momondo provides multiple filters to help you find the best flight to Ontario from Seattle. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

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

Price alerts on flights to Ontario from Seattle are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

An easier way to manage your Ontario trip

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