S$105 Cheap Flights from Seattle to Ontario

View S$105 flight on Tue, 10 Jun, 2025Opens in a new window

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

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Cheap Flights from Seattle to Ontario (SEA-ONT)

Prices were available within the past 7 days and start at S$105 for one-way flights and S$210 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 27 May - Tue, 3 Jun
SEA
Seattle
ONT
Ontario
S$210 Return, found 5 days ago
S$210
Return
found 5 days ago
Select Delta flight, departing Tue, 27 May from Seattle to Ontario, returning Tue, 3 Jun, priced at S$210 found 5 days ago
Delta
Tue, 27 May - Tue, 3 Jun
SEA
Seattle
ONT
Ontario
S$224 Return, found 5 days ago
S$224
Return
found 5 days ago
Select Delta flight, departing Tue, 27 May from Seattle to Ontario, returning Tue, 3 Jun, priced at S$224 found 5 days ago
Delta
Tue, 27 May - Tue, 3 Jun
SEA
Seattle
ONT
Ontario
S$237 Return, found 5 days ago
S$237
Return
found 5 days ago
Select Delta flight, departing Tue, 27 May from Seattle to Ontario, returning Tue, 3 Jun, priced at S$237 found 5 days ago
Delta
Fri, 2 May - Wed, 7 May
SEA
Seattle
ONT
Ontario
S$261 Return, found 2 days ago
S$261
Return
found 2 days ago
Select Delta flight, departing Fri, 2 May from Seattle to Ontario, returning Wed, 7 May, priced at S$261 found 2 days ago
Delta
Tue, 27 May - Tue, 3 Jun
SEA
Seattle
ONT
Ontario
S$271 Return, found 5 days ago
S$271
Return
found 5 days ago
Select Delta flight, departing Tue, 27 May from Seattle to Ontario, returning Tue, 3 Jun, priced at S$271 found 5 days ago
Delta
Thu, 29 May - Thu, 5 Jun
SEA
Seattle
ONT
Ontario
S$278 Return, found 3 days ago
S$278
Return
found 3 days ago
Select Delta flight, departing Thu, 29 May from Seattle to Ontario, returning Thu, 5 Jun, priced at S$278 found 3 days ago
Delta
Thu, 29 May - Thu, 5 Jun
SEA
Seattle
ONT
Ontario
S$284 Return, found 3 days ago
S$284
Return
found 3 days ago
Select Delta flight, departing Thu, 29 May from Seattle to Ontario, returning Thu, 5 Jun, priced at S$284 found 3 days ago
United
Thu, 29 May - Thu, 5 Jun
SEA
Seattle
ONT
Ontario
S$325 Return, found 3 days ago
S$325
Return
found 3 days ago
Select United flight, departing Thu, 29 May from Seattle to Ontario, returning Thu, 5 Jun, priced at S$325 found 3 days ago
American Airlines
Fri, 2 May - Wed, 7 May
SEA
Seattle
ONT
Ontario
S$380 Return, found 2 days ago
S$380
Return
found 2 days ago
Select American Airlines flight, departing Fri, 2 May from Seattle to Ontario, returning Wed, 7 May, priced at S$380 found 2 days ago
Alaska Airlines
Tue, 27 May - Tue, 3 Jun
PAE
Seattle
ONT
Ontario
S$1,020 Return, found 5 days ago
S$1,020
Return
found 5 days ago
Select Alaska Airlines flight, departing Tue, 27 May from Seattle to Ontario, returning Tue, 3 Jun, priced at S$1,020 found 5 days ago

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 S$210. 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 cancelled 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 kilometres. 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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