Cheap Flights from Seattle (SEA) to Ontario (ONT) from HK$777~

View HK$777 flight on Sat, 2 May 2026Opens in a new window

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

  • Be in the know

    Get alerts if flight prices drop or rise*

  • Book smarter

    Save up to 35% on select hotels after you book a flight*

  • Earn twice

    Earn your airline miles on top of our rewards
    Sign in

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

Prices were available within the past 7 days and start at HK$777 for one-way flights and HK$1,231 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 21 Apr - Wed, 29 Apr
SEA
Seattle
ONT
Ontario
HK$1,231 Return, found 1 day ago
HK$1,231
Return
found 1 day ago
Select Delta flight, departing Tue, 21 Apr from Seattle to Ontario, returning Wed, 29 Apr, priced at HK$1,231 found 1 day ago
Delta
Tue, 28 Apr - Tue, 5 May
SEA
Seattle
ONT
Ontario
HK$1,468 Return, found 6 days ago
HK$1,468
Return
found 6 days ago
Select Delta flight, departing Tue, 28 Apr from Seattle to Ontario, returning Tue, 5 May, priced at HK$1,468 found 6 days ago
Delta
Wed, 22 Apr - Wed, 6 May
SEA
Seattle
ONT
Ontario
HK$1,704 Return, found 6 days ago
HK$1,704
Return
found 6 days ago
Select Delta flight, departing Wed, 22 Apr from Seattle to Ontario, returning Wed, 6 May, priced at HK$1,704 found 6 days ago
Delta
Tue, 21 Apr - Tue, 28 Apr
SEA
Seattle
ONT
Ontario
HK$1,791 Return, found 6 days ago
HK$1,791
Return
found 6 days ago
Select Delta flight, departing Tue, 21 Apr from Seattle to Ontario, returning Tue, 28 Apr, priced at HK$1,791 found 6 days ago
United
Tue, 28 Apr - Tue, 5 May
SEA
Seattle
ONT
Ontario
HK$1,824 Return, found 6 days ago
HK$1,824
Return
found 6 days ago
Select United flight, departing Tue, 28 Apr from Seattle to Ontario, returning Tue, 5 May, priced at HK$1,824 found 6 days ago
Delta
Tue, 28 Apr - Tue, 5 May
SEA
Seattle
ONT
Ontario
HK$1,932 Return, found 6 days ago
HK$1,932
Return
found 6 days ago
Select Delta flight, departing Tue, 28 Apr from Seattle to Ontario, returning Tue, 5 May, priced at HK$1,932 found 6 days ago
United
Tue, 21 Apr - Tue, 28 Apr
SEA
Seattle
ONT
Ontario
HK$1,976 Return, found 6 days ago
HK$1,976
Return
found 6 days ago
Select United flight, departing Tue, 21 Apr from Seattle to Ontario, returning Tue, 28 Apr, priced at HK$1,976 found 6 days ago
United
Tue, 21 Apr - Wed, 29 Apr
SEA
Seattle
ONT
Ontario
HK$2,136 Return, found 1 day ago
HK$2,136
Return
found 1 day ago
Select United flight, departing Tue, 21 Apr from Seattle to Ontario, returning Wed, 29 Apr, priced at HK$2,136 found 1 day ago
American Airlines
Tue, 21 Apr - Wed, 29 Apr
SEA
Seattle
ONT
Ontario
HK$2,255 Return, found 1 day ago
HK$2,255
Return
found 1 day ago
Select American Airlines flight, departing Tue, 21 Apr from Seattle to Ontario, returning Wed, 29 Apr, priced at HK$2,255 found 1 day ago
Alaska Airlines
Thu, 5 Feb - Fri, 6 Feb
SEA
Seattle
ONT
Ontario
HK$2,951 Return, found 9 hours ago
HK$2,951
Return
found 9 hours ago
Select Alaska Airlines flight, departing Thu, 5 Feb from Seattle to Ontario, returning Fri, 6 Feb, priced at HK$2,951 found 9 hours ago

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

October is typically the cheapest month to fly

From HK$614 - HK$1,239 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$1,231
Distance
1530 km
Average flight time
2 hours 39 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$777 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$1,231. 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.

Explore a world of travel with Expedia

*Available to Expedia members.