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Cheap flights from Seattle to Los Angeles from C$ 98

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 26/8. 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

Frontier Logo
8:27 p.m. - 11:09 p.m.SEA-ONT
2h 42mdirect
Frontier Logo
9:40 a.m. - 12:25 p.m.ONT-SEA
2h 45mdirect
C$ 155Frontier
Find Deal
Sat, 23 Aug - Thu, 28 Aug
Delta Logo
8:15 a.m. - 11:08 a.m.SEA-ONT
2h 53mdirect
Delta Logo
11:48 a.m. - 2:45 p.m.ONT-SEA
2h 57mdirect
C$ 216Delta
Find Deal
Tue, 21 Oct - Sat, 25 Oct
Frontier Logo
6:25 a.m. - 11:50 p.m.SEA-ONT
17h 25m1 stop
Frontier Logo
9:40 a.m. - 12:25 p.m.ONT-SEA
2h 45mdirect
C$ 232Frontier
Find Deal
Sat, 23 Aug - Thu, 28 Aug
Alaska Airlines Logo
7:55 a.m. - 10:44 a.m.SEA-ONT
2h 49mdirect
Alaska Airlines Logo
6:00 a.m. - 8:45 a.m.ONT-SEA
2h 45mdirect
C$ 242Alaska Airlines
Find Deal
Sat, 23 Aug - Sun, 24 Aug
Alaska Airlines Logo
5:20 a.m. - 9:26 a.m.SEA-ONT
4h 06m1 stop
Alaska Airlines Logo
11:39 a.m. - 2:19 p.m.ONT-SEA
2h 40mdirect
C$ 249Alaska Airlines
Find Deal
Tue, 30 Sep - Tue, 30 Sep
Southwest Logo
11:10 a.m. - 5:30 p.m.SEA-ONT
6h 20m2 stops
Southwest Logo
10:00 a.m. - 3:10 p.m.ONT-SEA
5h 10m1 stop
C$ 250Southwest
Find Deal
Tue, 23 Sep - Wed, 24 Sep
United Airlines Logo
7:00 a.m. - 12:13 p.m.SEA-ONT
5h 13m1 stop
United Airlines Logo
6:50 p.m. - 10:59 p.m.ONT-SEA
4h 09m1 stop
C$ 268United Airlines
Find Deal
Mon, 15 Sep - Tue, 16 Sep
Southwest Logo
7:55 a.m. - 12:30 p.m.SEA-ONT
4h 35m1 stop
Southwest Logo
5:20 a.m. - 12:35 p.m.ONT-SEA
7h 15m2 stops
C$ 278Southwest
Find Deal
Sat, 13 Sep - Mon, 15 Sep
United Airlines Logo
5:31 p.m. - 10:52 p.m.SEA-ONT
5h 21m1 stop
United Airlines Logo
5:00 a.m. - 12:28 p.m.ONT-SEA
7h 28m1 stop
C$ 279United Airlines
Find Deal
Fri, 24 Oct - Sun, 2 Nov
Hawaiian Airlines Logo
7:55 a.m. - 10:44 a.m.SEA-ONT
2h 49mdirect
Hawaiian Airlines Logo
6:00 a.m. - 8:45 a.m.ONT-SEA
2h 45mdirect
C$ 337Hawaiian Airlines
Find Deal
Sat, 23 Aug - Sun, 24 Aug

Delta flights from Seattle to Ontario

Our best Delta deals on Seattle to Ontario flight tickets
Delta
21 Oct
SEA8:15 a.m.Seattle/Tacoma Intl
2h 53m
ONT11:08 a.m.Ontario
25 Oct
ONT11:48 a.m.Ontario
2h 57m
SEA2:45 p.m.Seattle/Tacoma Intl
C$ 216
Find similar
Delta
21 Oct
SEA8:15 a.m.Seattle/Tacoma Intl
2h 53m
ONT11:08 a.m.Ontario
27 Oct
ONT6:37 a.m.Ontario
3h 03m
SEA9:40 a.m.Seattle/Tacoma Intl
C$ 243
Find similar
Delta
20 Sep
SEA8:15 a.m.Seattle/Tacoma Intl
2h 54m
ONT11:09 a.m.Ontario
21 Sep
ONT6:00 a.m.Ontario
2h 54m
SEA8:54 a.m.Seattle/Tacoma Intl
C$ 245
Find similar

Frontier flights from Seattle to Ontario

Our best Frontier deals on Seattle to Ontario flight tickets
Frontier
23 Aug
SEA8:27 p.m.Seattle/Tacoma Intl
2h 42m
ONT11:09 p.m.Ontario
28 Aug
ONT9:40 a.m.Ontario
2h 45m
SEA12:25 p.m.Seattle/Tacoma Intl
C$ 155
Find similar
Frontier
6 Aug
SEA1:42 p.m.Seattle/Tacoma Intl
2h 54m
ONT4:36 p.m.Ontario
10 Aug
ONT10:03 a.m.Ontario
2h 50m
SEA12:53 p.m.Seattle/Tacoma Intl
C$ 220
Find similar
Frontier
23 Aug
SEA6:25 a.m.Seattle/Tacoma Intl
17h 25m
1 stop
ONT11:50 p.m.Ontario
28 Aug
ONT9:40 a.m.Ontario
2h 45m
SEA12:25 p.m.Seattle/Tacoma Intl
C$ 232
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 July 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

Sat 23/8

8:27 p.m.-11:09 p.m.

Nonstop2h 42m

Ontario

Thu 28/8

9:40 a.m.-12:25 p.m.

Nonstop2h 45m

C$ 155

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 21/10

8:15 a.m.-11:08 a.m.

Nonstop2h 53m

Ontario

Sat 25/10

11:48 a.m.-2:45 p.m.

Nonstop2h 57m

C$ 216

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 23/8

6:25 a.m.-11:50 p.m.

1 stop17h 25m

Ontario

Thu 28/8

9:40 a.m.-12:25 p.m.

Nonstop2h 45m

C$ 232

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 23/8

7:55 a.m.-10:44 a.m.

Nonstop2h 49m

Ontario

Sun 24/8

6:00 a.m.-8:45 a.m.

Nonstop2h 45m

C$ 242

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 30/9

5:20 a.m.-9:26 a.m.

1 stop4h 06m

Ontario

Tue 30/9

11:39 a.m.-2:19 p.m.

Nonstop2h 40m

C$ 249

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 23/9

11:10 a.m.-5:30 p.m.

2 stops6h 20m

Ontario

Wed 24/9

10:00 a.m.-3:10 p.m.

1 stop5h 10m

C$ 250

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Mon 15/9

7:00 a.m.-12:13 p.m.

1 stop5h 13m

Ontario

Tue 16/9

6:50 p.m.-10:59 p.m.

1 stop4h 09m

C$ 268

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 13/9

7:55 a.m.-12:30 p.m.

1 stop4h 35m

Ontario

Mon 15/9

5:20 a.m.-12:35 p.m.

2 stops7h 15m

C$ 278

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Fri 24/10

5:31 p.m.-10:52 p.m.

1 stop5h 21m

Ontario

Sun 2/11

5:00 a.m.-12:28 p.m.

1 stop7h 28m

C$ 279

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 23/8

7:55 a.m.-10:44 a.m.

Nonstop2h 49m

Ontario

Sun 24/8

6:00 a.m.-8:45 a.m.

Nonstop2h 45m

C$ 337

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 Los Angeles from

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 September is, on average, the cheapest month to fly to Ontario from Seattle, with most prices found around C$ 187. The month of August is another great option to travel to Ontario, with average flight prices from Seattle averaging around C$ 232.

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 Saturday. momondo users have found tickets for Saturday departures for as low as C$ 130. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Monday 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$ 306.

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 at noon. Our users have found flights to Ontario at noon for as low as C$ 114. Try not to purchase tickets in the evening because they tend to be around C$ 271. 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$ 282 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$ 194 on momondo.

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

There are 1 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.

How have Seattle to Ontario flight prices changed over time?

As of July 2025, prices for Seattle to Ontario flights are approximately 14% 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$ 98

Fastest flight time

2h 32m

Direct flights

Every day

Airports in Ontario

1 airport
The best one-way flight to Ontario from Seattle in the past 72 hours is C$ 98. The best round-trip flight deal from Seattle to Ontario found on momondo in the last 72 hours is C$ 155.
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$ 97Free CancellationRating
5.9
3,237 reviews
Search Frontier flights
Alaska AirlinesPriceFrom C$ 215Free CancellationRating
8.0
10,000 reviews
Search Alaska Airlines flights

  • Alaska Airlines Flights From Seattle to Ontario

    Across 30 Alaska Airlines flights from Seattle to Ontario this week, the average price was C$ 220, with the best Alaska Airlines deals starting from C$ 156 round-trip. 10,000 users have rated Alaska Airlines on momondo, with an average score of 8.0/10.

  • Frontier Flights From Seattle to Ontario

    Frontier (5.9/10 from 3,237 reviews) operates around 7 flights from Seattle to Ontario in any given week. The average Frontier airfare for this route is around C$ 98, with deals from around C$ 70 rare but found on momondo. Referenced prices are for round-trip Seattle to Ontario flight searches in the last 72 hours.

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.

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