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Cheap flights from Seattle to Los Angeles from $62

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 1/30. 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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Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
12:54 pm - 6:40 pm
SEA
-
ONT
5h 46m1 stop
Frontier Logo
3:22 pm - 9:36 am
ONT
-
SEA
18h 14m1 stop
$128Frontier
Sat, Jan 24 - Thu, Jan 29
Frontier Logo
12:34 pm - 12:20 am
SEA
-
ONT
11h 46m1 stop
Frontier Logo
6:20 am - 11:19 am
ONT
-
SEA
28h 59m1 stop
$129Frontier
Fri, Feb 6 - Sun, Feb 8
Multiple Airlines Logo
8:15 am - 10:59 am
SEA
-
ONT
2h 44mnonstop
Multiple Airlines Logo
5:15 pm - 8:08 pm
ONT
-
SEA
2h 53mnonstop
$135Multiple Airlines
Sun, Jan 11 - Sun, Jan 11
Southwest Logo
6:15 am - 1:15 pm
SEA
-
ONT
7h 00m1 stop
Southwest Logo
2:25 pm - 10:30 pm
ONT
-
SEA
8h 05m1 stop
$136Southwest
Thu, Jan 1 - Thu, Jan 8
Alaska Airlines Logo
8:56 pm - 11:32 pm
SEA
-
ONT
2h 36mnonstop
Alaska Airlines Logo
4:02 pm - 6:52 pm
ONT
-
SEA
2h 50mnonstop
$137Alaska Airlines
Sat, Feb 21 - Sat, Feb 28
Alaska Airlines Logo
9:35 pm - 12:14 am
SEA
-
ONT
2h 39mnonstop
Alaska Airlines Logo
4:36 pm - 7:27 pm
ONT
-
SEA
2h 51mnonstop
$138Alaska Airlines
Fri, Jan 2 - Tue, Jan 6
Delta Logo
11:15 am - 1:56 pm
SEA
-
ONT
2h 41mnonstop
Delta Logo
3:30 pm - 6:35 pm
ONT
-
SEA
3h 05mnonstop
$139Delta
Tue, Jan 6 - Fri, Jan 9
Alaska Airlines Logo
8:35 pm - 7:16 pm
SEA
-
ONT
22h 41m1 stop
Alaska Airlines Logo
6:00 am - 8:54 am
ONT
-
SEA
2h 54mnonstop
$141Alaska Airlines
Fri, Jan 16 - Sun, Jan 18
Alaska Airlines Logo
9:35 pm - 12:14 am
SEA
-
ONT
2h 39mnonstop
Alaska Airlines Logo
7:56 pm - 6:33 pm
ONT
-
SEA
22h 37m1 stop
$142Alaska Airlines
Wed, Dec 31 - Wed, Jan 7
Frontier Logo
11:06 am - 1:42 pm
SEA
-
ONT
2h 36mnonstop
Frontier Logo
2:34 pm - 7:47 pm
ONT
-
SEA
5h 13m1 stop
$145Frontier
Mon, Jan 5 - Fri, Jan 9

Southwest flights from Seattle to Ontario

Our best Southwest deals on Seattle to Ontario flight tickets
Southwest
Jan 1
SEA6:15 amSeattle/Tacoma Intl
7h 00m
1 stop
ONT1:15 pmOntario
Jan 8
ONT2:25 pmOntario
8h 05m
1 stop
SEA10:30 pmSeattle/Tacoma Intl
$136
Find similar
Southwest
Jan 14
SEA1:20 pmSeattle/Tacoma Intl
7h 00m
2 stops
ONT8:20 pmOntario
Jan 21
ONT5:35 pmOntario
4h 15m
1 stop
SEA9:50 pmSeattle/Tacoma Intl
$150
Find similar
Southwest
Jan 15
SEA9:50 amSeattle/Tacoma Intl
4h 15m
1 stop
ONT2:05 pmOntario
Jan 20
ONT3:25 pmOntario
7h 40m
2 stops
SEA11:05 pmSeattle/Tacoma Intl
$160
Find similar

Alaska Airlines flights from Seattle to Ontario

Our best Alaska Airlines deals on Seattle to Ontario flight tickets
Alaska Airlines
Mar 5
SEA8:56 pmSeattle/Tacoma Intl
2h 36m
ONT11:32 pmOntario
Mar 9
ONT6:14 amOntario
2h 55m
SEA9:09 amSeattle/Tacoma Intl
$137
Find similar
Alaska Airlines
Jan 2
SEA7:10 amSeattle/Tacoma Intl
2h 40m
ONT9:50 amOntario
Jan 9
ONT11:53 amOntario
2h 51m
SEA2:44 pmSeattle/Tacoma Intl
$138
Find similar
Alaska Airlines
Jan 16
SEA9:36 pmSeattle/Tacoma Intl
21h 40m
1 stop
ONT7:16 pmOntario
Jan 21
ONT11:53 amOntario
2h 51m
SEA2:44 pmSeattle/Tacoma Intl
$141
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 832,500 searches. Data last updated December 4, 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 1/24

12:54 pm-6:40 pm

1 stop5h 46m

Ontario

Thu 1/29

3:22 pm-9:36 am

1 stop18h 14m

$128

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Fri 2/6

12:34 pm-12:20 am

1 stop11h 46m

Ontario

Sun 2/8

6:20 am-11:19 am

1 stop28h 59m

$129

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sun 1/11

8:15 am-10:59 am

Nonstop2h 44m

Ontario

Sun 1/11

5:15 pm-8:08 pm

Nonstop2h 53m

$135

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 1/1

6:15 am-1:15 pm

1 stop7h 00m

Ontario

Thu 1/8

2:25 pm-10:30 pm

1 stop8h 05m

$136

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 2/21

8:56 pm-11:32 pm

Nonstop2h 36m

Ontario

Sat 2/28

4:02 pm-6:52 pm

Nonstop2h 50m

$137

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Fri 1/2

9:35 pm-12:14 am

Nonstop2h 39m

Ontario

Tue 1/6

4:36 pm-7:27 pm

Nonstop2h 51m

$138

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 1/6

11:15 am-1:56 pm

Nonstop2h 41m

Ontario

Fri 1/9

3:30 pm-6:35 pm

Nonstop3h 05m

$139

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Fri 1/16

8:35 pm-7:16 pm

1 stop22h 41m

Ontario

Sun 1/18

6:00 am-8:54 am

Nonstop2h 54m

$141

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 12/31

9:35 pm-12:14 am

Nonstop2h 39m

Ontario

Wed 1/7

7:56 pm-6:33 pm

1 stop22h 37m

$142

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Mon 1/5

11:06 am-1:42 pm

Nonstop2h 36m

Ontario

Fri 1/9

2:34 pm-7:47 pm

1 stop5h 13m

$145

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest 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?

In general, January is the cheapest month to fly from Seattle to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $187. If you aren’t able to travel during the month of January, then book flights to Ontario from Seattle during October instead. Flights to Ontario in October, while not as cheap as those in January, still average around $187.

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

The cheapest day to depart on your flight to Ontario is on a Sunday when prices can be found for as low as $213. This is often the case because there is less demand to fly during this day of the week. When flying out on a Monday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to Ontario for around $235.

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

At noon is the cheapest time of day to fly from Seattle to Ontario when you can find flight prices for as low as $196. Flying to Ontario at noon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the evening when prices are $251 on average. Flights to Ontario from Seattle in the evening are generally more expensive because this time of day is more convenient for travelers’ schedules.

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 $224 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 $179 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.

How have Seattle to Ontario flight prices changed over time?

As of December 2025, prices for Seattle to Ontario flights are approximately 45% cheaper 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

$114

Fastest flight time

2h 33m

Direct flights

Every day

Airports in Ontario

1 airport
The best one-way flight to Ontario from Seattle in the past 72 hours is $114. The best round-trip flight deal from Seattle to Ontario found on momondo in the last 72 hours is $212.
The fastest flight from Seattle to Ontario takes 2h 33m
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?

    The distance between Seattle/Tacoma Intl and Ontario is about 966.6 mi. A reasonable flight in good conditions will take 2h 33m.

  • 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 are refreshed on a daily basis.

  • 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?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, 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 $71Free CancellationRating
5.8
3,092 reviews
Search Frontier flights
Hawaiian AirlinesPriceFrom $98Free CancellationRating
7.8
2,815 reviews
Search Hawaiian Airlines flights
DeltaPriceFrom $118Free CancellationRating
7.9
8,011 reviews
Search Delta flights
SouthwestPriceFrom $130Free CancellationRating
8.0
4,254 reviews
Search Southwest flights
Alaska AirlinesPriceFrom $156Free CancellationRating
8.0
11,396 reviews
Search Alaska Airlines flights

  • Alaska Airlines Flights From Seattle to Ontario

    Alaska Airlines flies from Seattle to Ontario around 12 times per week, with 11,396 momondo users rating the airline 8.0/10. The cheapest Alaska Airlines deal from Seattle to Ontario in the last 72 hours was $156 (round-trip), much lower than the average airfare cost of $291 for Alaska Airlines flights on this route.

  • Delta Flights From Seattle to Ontario

    Delta (7.9/10 from 8,011 reviews) operates around 8 flights from Seattle to Ontario in any given week. The average Delta airfare for this route is around $256, with deals from around $118 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?

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Seattle to Ontario for you.

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

Yes. momondo allows you to filter the results for Seattle to Ontario flights to just show those with flexible booking policies.

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

momondo helps you find the best flight between Seattle and Ontario by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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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