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Cheap flights from Seattle to Los Angeles from $55

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 8/12. 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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Cheap round-trip flights

Frontier Logo
8:42 pm - 11:24 pmSEA-ONT
2h 42mnonstop
Frontier Logo
5:03 pm - 7:53 pmONT-SEA
2h 50mnonstop
$113Frontier
Find Deal
Wed, Aug 27 - Tue, Sep 2
Frontier Logo
1:42 pm - 4:36 pmSEA-ONT
2h 54mnonstop
Frontier Logo
5:03 pm - 7:53 pmONT-SEA
2h 50mnonstop
$128Frontier
Find Deal
Tue, Aug 12 - Tue, Aug 19
Frontier Logo
2:37 pm - 5:16 pmSEA-ONT
2h 39mnonstop
Frontier Logo
10:46 am - 1:42 pmONT-SEA
2h 56mnonstop
$136Frontier
Find Deal
Fri, Nov 7 - Mon, Nov 10
Frontier Logo
1:42 pm - 4:36 pmSEA-ONT
2h 54mnonstop
Frontier Logo
10:03 am - 12:53 pmONT-SEA
2h 50mnonstop
$138Frontier
Find Deal
Wed, Aug 6 - Wed, Aug 13
Frontier Logo
1:42 pm - 4:36 pmSEA-ONT
2h 54mnonstop
Frontier Logo
10:03 am - 12:53 pmONT-SEA
2h 50mnonstop
$139Frontier
Find Deal
Tue, Aug 12 - Sat, Aug 16
Frontier Logo
1:42 pm - 4:36 pmSEA-ONT
2h 54mnonstop
Frontier Logo
5:03 pm - 7:53 pmONT-SEA
2h 50mnonstop
$140Frontier
Find Deal
Wed, Aug 13 - Wed, Aug 20
Delta Logo
8:05 am - 10:50 amSEA-ONT
2h 45mnonstop
Delta Logo
11:40 am - 2:25 pmONT-SEA
2h 45mnonstop
$157Delta
Find Deal
Tue, Sep 2 - Wed, Sep 10
Alaska Airlines Logo
7:55 am - 10:44 amSEA-ONT
2h 49mnonstop
Alaska Airlines Logo
3:06 pm - 5:46 pmONT-SEA
2h 40mnonstop
$167Alaska Airlines
Find Deal
Sat, Aug 30 - Tue, Sep 9
Delta Logo
7:50 pm - 10:42 pmSEA-ONT
2h 52mnonstop
Delta Logo
11:40 am - 2:25 pmONT-SEA
2h 45mnonstop
$177Delta
Find Deal
Thu, Sep 4 - Wed, Sep 10
Alaska Airlines Logo
12:00 pm - 2:46 pmSEA-ONT
2h 46mnonstop
Alaska Airlines Logo
6:10 pm - 11:02 pmONT-SEA
4h 52m1 stop
$181Alaska Airlines
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Tue, Aug 12 - Tue, Aug 12

Frontier flights from Seattle to Ontario

Our best Frontier deals on Seattle to Ontario flight tickets
Frontier
Aug 27
SEA8:42 pmSeattle/Tacoma Intl
2h 42m
ONT11:24 pmOntario
Sep 2
ONT5:03 pmOntario
2h 50m
SEA7:53 pmSeattle/Tacoma Intl
$113
Find similar
Frontier
Aug 12
SEA1:42 pmSeattle/Tacoma Intl
2h 54m
ONT4:36 pmOntario
Aug 19
ONT5:03 pmOntario
2h 50m
SEA7:53 pmSeattle/Tacoma Intl
$128
Find similar
Frontier
Nov 7
SEA2:37 pmSeattle/Tacoma Intl
2h 39m
ONT5:16 pmOntario
Nov 10
ONT10:46 amOntario
2h 56m
SEA1:42 pmSeattle/Tacoma Intl
$136
Find similar

Delta flights from Seattle to Ontario

Our best Delta deals on Seattle to Ontario flight tickets
Delta
Sep 2
SEA8:05 amSeattle/Tacoma Intl
2h 45m
ONT10:50 amOntario
Sep 10
ONT11:40 amOntario
2h 45m
SEA2:25 pmSeattle/Tacoma Intl
$157
Find similar
Delta
Sep 4
SEA7:50 pmSeattle/Tacoma Intl
2h 52m
ONT10:42 pmOntario
Sep 10
ONT11:40 amOntario
2h 45m
SEA2:25 pmSeattle/Tacoma Intl
$177
Find similar

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?

In general, September 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 $136. If you aren’t able to travel during the month of September, then book flights to Ontario from Seattle during August instead. Flights to Ontario in August, while not as cheap as those in September, still average around $171.

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 Thursday when prices can be found for as low as $185. 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 $221.

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 $176. 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 morning when prices are $224 on average. Flights to Ontario from Seattle in the morning 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 $205 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 $142 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 July 2025, prices for Seattle to Ontario flights are approximately 7% 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

$55

Fastest flight time

2h 39m

Direct flights

Every day

Airports in Ontario

1 airport
The best one-way flight to Ontario from Seattle in the past 72 hours is $55. The best round-trip flight deal from Seattle to Ontario found on momondo in the last 72 hours is $113.
The fastest flight from Seattle to Ontario takes 2h 39m
Direct flights go from Seattle to Ontario every day.
There is 1 airport near Ontario: Ontario (ONT)
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  • 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 39m.

  • 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 $58Free CancellationRating
5.9
3,261 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $59Free CancellationRating
6.3
8,046 reviews
Search Spirit Airlines flights
Hawaiian AirlinesPriceFrom $98Free CancellationRating
7.8
2,571 reviews
Search Hawaiian Airlines flights
DeltaPriceFrom $117Free CancellationRating
8.0
7,956 reviews
Search Delta flights
Alaska AirlinesPriceFrom $136Free CancellationRating
8.0
10,000 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $196Free CancellationRating
8.0
4,244 reviews
Search Southwest flights

  • Delta Flights From Seattle to Ontario

    Delta flies from Seattle to Ontario around 17 times per week, with 7,956 momondo users rating the airline 8.0/10. The cheapest Delta deal from Seattle to Ontario in the last 72 hours was $117 (round-trip), much lower than the average airfare cost of $257 for Delta flights on this route.

  • Alaska Airlines Flights From Seattle to Ontario

    Alaska Airlines (8.0/10 from 10,000 reviews) operates around 31 flights from Seattle to Ontario in any given week. The average Alaska Airlines airfare for this route is around $270, with deals from around $136 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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