Cheap Flights from Ontario (ONT) to Seattle (SEA) from HK$626~

View HK$626 flight on Thu, 18 Dec 2025Opens in a new window

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

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

Prices were available within the past 7 days and start at HK$626 for one-way flights and HK$1,542 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$1,542 Return, found 3 days ago
HK$1,542
Return
found 3 days ago
Select Delta flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$1,542 found 3 days ago
Delta
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$1,618 Return, found 3 days ago
HK$1,618
Return
found 3 days ago
Select Delta flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$1,618 found 3 days ago
Alaska Airlines
Tue, 16 Dec - Sat, 20 Dec
ONT
Ontario
SEA
Seattle
HK$2,046 Return, found 4 days ago
HK$2,046
Return
found 4 days ago
Select Alaska Airlines flight, departing Tue, 16 Dec from Ontario to Seattle, returning Sat, 20 Dec, priced at HK$2,046 found 4 days ago
United
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$2,048 Return, found 3 days ago
HK$2,048
Return
found 3 days ago
Select United flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$2,048 found 3 days ago
Delta
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$2,079 Return, found 3 days ago
HK$2,079
Return
found 3 days ago
Select Delta flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$2,079 found 3 days ago
Delta
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$2,090 Return, found 3 days ago
HK$2,090
Return
found 3 days ago
Select Delta flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$2,090 found 3 days ago
Delta
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$2,145 Return, found 3 days ago
HK$2,145
Return
found 3 days ago
Select Delta flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$2,145 found 3 days ago
Delta
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$2,155 Return, found 3 days ago
HK$2,155
Return
found 3 days ago
Select Delta flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$2,155 found 3 days ago
Delta
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$2,166 Return, found 3 days ago
HK$2,166
Return
found 3 days ago
Select Delta flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$2,166 found 3 days ago
American Airlines
Thu, 18 Dec - Thu, 25 Dec
ONT
Ontario
SEA
Seattle
HK$2,629 Return, found 3 days ago
HK$2,629
Return
found 3 days ago
Select American Airlines flight, departing Thu, 18 Dec from Ontario to Seattle, returning Thu, 25 Dec, priced at HK$2,629 found 3 days ago

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

October is typically the cheapest month to fly

From HK$614 - HK$1,239 per traveller.

Alternative airports near Seattle

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Seattle - Tacoma Intl. SEA. Cheapest option available. Average driving time to city centre is 20 minutes. Flights from HK$3,100
SEA
Seattle - Tacoma Intl.
Cheapest
Average driving time to city centre20 min
Flights from HK$3,100
Ontario to Seattle route information
Origin airport
Los Angeles - Ontario Intl.
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Delta
Return price
HK$1,401
Distance
1530 km
Average flight time
2 hours 56 mins

Flights from Los Angeles to Seattle

Book cheap flights from Los Angeles (ONT) to Seattle (SEA) 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 Los Angeles (ONT) to Seattle (SEA) 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 Los Angeles (ONT) to Seattle (SEA) trip. Call us at 3077-4857 (direct number - 24 hours day for English).

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

If you would like to book flights to Seattle more flexibly, many prefer to purchase one-way tickets with options to take different airlines. A one way ticket to Seattle is HK$626 now!

 

Frequently asked questions

How much is a flight from Ontario Airport to Sea-Tac Airport?
If you're traveling between Ontario Airport and Seattle - Tacoma Intl. Airport (SEA), round-trip journeys start from HK$1,542. This figure is based on fares quoted within the last 7 days on Expedia for flights departing within the next year, so don't hang about. Book now and save yourself both money and time. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from Los Angeles - Ontario Intl. Airport (ONT) to Sea-Tac Airport?
We understand that things come up unexpectedly, so we've made it as simple as possible for you to cancel your trip online. Just visit the Customer Service Portal and follow the instructions.
How do I find cheap flights from Ontario Airport to Seattle - Tacoma Intl. Airport (SEA) 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 Los Angeles - Ontario Intl. Airport (ONT) to Seattle - Tacoma Intl. Airport (SEA) flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Los Angeles - Ontario Intl. Airport (ONT) to SEA?
The flight distance from Los Angeles - Ontario Intl. Airport (ONT) to Sea-Tac Airport is 1,550 kilometers. Pack yourself a drink, some snacks and an interesting novel to read. Keep yourself busy in the air and time will zip by.
Which airlines fly direct from Los Angeles - Ontario Intl. Airport (ONT) to Seattle - Tacoma Intl. Airport (SEA)?
Many travelers choose to fly with Alaska Airlines (AS) from Ontario Airport to Seattle - Tacoma Intl. Airport (SEA). This leading airline offers 117 flights monthly, so you can easily find a flight time that works for you. Another carrier operating on this route is Delta Air Lines (DL). You'll have 86 flights every month to choose from.
Are Ontario Airport to Seattle - Tacoma Intl. Airport (SEA) flight tickets cheaper when they're purchased at the last minute?
Last-minute planners can sometimes pick up a bargain, with some super cheap airfares from ONT to Sea-Tac Airport popping up a few weeks prior to the departure date. If you'd rather book ahead of time, Expedia compares and updates all the best flight deals regularly — as early as a year in advance in some cases. It does depend on the carrier though, as not all airlines release prices so far in advance.

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