Cheap Flights from Seattle (SEA) to Ontario (ONT) from HK$851~

View HK$851 flight on Tue, 2 Dec 2025Opens in a new window

Popular airlines from Seattle-Tacoma International Airport (SEA) to Los Angeles - Ontario Intl. Airport (ONT)

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Find Cheap Flights from Seattle (SEA) to Ontario (ONT)

Prices were available within the past 7 days and start at HK$851 for one-way flights and HK$1,380 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$1,380 Return, found 1 day ago
HK$1,380
Return
found 1 day ago
Select Delta flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$1,380 found 1 day ago
Delta
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$1,928 Return, found 1 day ago
HK$1,928
Return
found 1 day ago
Select Delta flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$1,928 found 1 day ago
Delta
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$1,961 Return, found 1 day ago
HK$1,961
Return
found 1 day ago
Select Delta flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$1,961 found 1 day ago
Delta
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$2,047 Return, found 1 day ago
HK$2,047
Return
found 1 day ago
Select Delta flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$2,047 found 1 day ago
Alaska Airlines
Sat, 20 Dec - Tue, 23 Dec
SEA
Seattle
ONT
Ontario
HK$2,079 Return, found 1 day ago
HK$2,079
Return
found 1 day ago
Select Alaska Airlines flight, departing Sat, 20 Dec from Seattle to Ontario, returning Tue, 23 Dec, priced at HK$2,079 found 1 day ago
American Airlines
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$2,080 Return, found 1 day ago
HK$2,080
Return
found 1 day ago
Select American Airlines flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$2,080 found 1 day ago
Delta
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$2,090 Return, found 1 day ago
HK$2,090
Return
found 1 day ago
Select Delta flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$2,090 found 1 day ago
Delta
Fri, 17 Jul - Sun, 19 Jul
SEA
Seattle
ONT
Ontario
HK$2,165 Return, found 3 days ago
HK$2,165
Return
found 3 days ago
Select Delta flight, departing Fri, 17 Jul from Seattle to Ontario, returning Sun, 19 Jul, priced at HK$2,165 found 3 days ago
Delta
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$2,240 Return, found 1 day ago
HK$2,240
Return
found 1 day ago
Select Delta flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$2,240 found 1 day ago
United
Tue, 2 Dec - Tue, 9 Dec
SEA
Seattle
ONT
Ontario
HK$2,316 Return, found 1 day ago
HK$2,316
Return
found 1 day ago
Select United flight, departing Tue, 2 Dec from Seattle to Ontario, returning Tue, 9 Dec, priced at HK$2,316 found 1 day ago

Find the cheapest month to fly from Seattle (SEA) to Ontario (ONT)

November is typically the cheapest month to fly

From HK$614 - HK$1,797 per traveller.
Seattle to Ontario route information
Origin airport
Seattle - Tacoma Intl.
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, United
Return price
HK$1,380
Distance
1530 km
Average flight time
2 hours 42 mins

Flights from Seattle to Los Angeles

Book cheap flights from Seattle (SEA) to Los Angeles (ONT) on Expedia.com.hk. Find the best flight deals to destinations around the world for your next leisure or business travel on Expedia.com.hk.

Search for flights from Seattle (SEA) to Los Angeles (ONT) to find great flight deals suitable to your travel date and time. Expedia.com.hk flight booking search engine is simple to use and looking for cheap flights is as easy as a click of a mouse or on your mobile devices.

Be assured that you’re seeing the best price guaranteed! Our friendly customer service representatives are here to serve you 24 hours day to provide assistance and answer any questions that you may have about booking your Seattle (SEA) to Los Angeles (ONT) trip. Call us at 3077-4857 (direct number - 24 hours day for English).

Save more when combine your Los Angeles flight with a hotel for a package deal! Discover additional savings by booking in advance. Now you can find activities in Los Angeles and things to do in Los Angeles for your perfect vacation with Expedia Thing to Do.

If you would like to book flights to Los Angeles more flexibly, many prefer to purchase one-way tickets with options to take different airlines. A one way ticket to Los Angeles is HK$851 now!

 

Frequently asked questions

How much is a flight from Seattle - Tacoma Intl. Airport (SEA) to ONT?
Based on airfares available within the last 7 days on Expedia for flights departing within the next year, round-trip flights between Sea-Tac Airport and Los Angeles - Ontario Intl. Airport (ONT) start from HK$1,380. Make your booking ASAP to score the best price for your big adventure. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from SEA to Los Angeles - Ontario Intl. Airport (ONT)?
The majority of flights can be canceled online, but every airline has its own set of terms and conditions. If you do need to cancel your flight, check out our Customer Service Portal and follow the instructions.
How do I find cheap flights from SEA to Los Angeles - Ontario Intl. Airport (ONT) that have flexible change policies?
Many airlines offer the option to reschedule your flight without a change fee. All you pay is the difference between the original flight and the new flight. When you're searching for Seattle - Tacoma Intl. Airport (SEA) to Los Angeles - Ontario Intl. Airport (ONT) flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Sea-Tac Airport to ONT?
The flying distance between Sea-Tac Airport and Los Angeles - Ontario Intl. Airport (ONT) is 1,550 kilometers. Close your eyes or get stuck into a book and the journey will zip on by.
Which airlines fly direct from Sea-Tac Airport to Ontario Airport?
One airline that services the route from Seattle - Tacoma Intl. Airport (SEA) to Los Angeles - Ontario Intl. Airport (ONT) is Alaska Airlines (AS). It offers 117 flights every month. Another carrier servicing this route is Delta Air Lines (DL). You'll have 86 flights each month to select from.
Are SEA to ONT flight tickets cheaper when they're purchased at the last minute?
It is possible to nab a fantastic last-minute deal from SEA to Ontario Airport, but it can also be hit-or-miss. As many airlines release prices up to a year in advance, it's worthwhile keeping an eye on fares early and being ready to book when you see a bargain. Expedia compares carrier prices and updates flight deals often, so you can rest easy knowing you're always getting the latest offers.

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