S$153 Cheap Flights from Ontario Intl. Airport to Seattle

View S$153 flight on Sat, 30 May, 2026Opens in a new window

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

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Cheap Flights from Ontario Intl. Airport to Seattle (ONT-SEA)

Prices were available within the past 7 days and start at S$153 for one-way flights and S$253 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 2 Jun - Sat, 6 Jun
ONT
Ontario
SEA
Seattle
S$253 Return, found 5 days ago
S$253
Return
found 5 days ago
Select Delta flight, departing Tue, 2 Jun from Ontario to Seattle, returning Sat, 6 Jun, priced at S$253 found 5 days ago
Delta
Sat, 30 May - Sun, 7 Jun
ONT
Ontario
SEA
Seattle
S$265 Return, found 5 days ago
S$265
Return
found 5 days ago
Select Delta flight, departing Sat, 30 May from Ontario to Seattle, returning Sun, 7 Jun, priced at S$265 found 5 days ago
Delta
Thu, 28 May - Fri, 5 Jun
ONT
Ontario
SEA
Seattle
S$278 Return, found 5 days ago
S$278
Return
found 5 days ago
Select Delta flight, departing Thu, 28 May from Ontario to Seattle, returning Fri, 5 Jun, priced at S$278 found 5 days ago
Delta
Tue, 2 Jun - Fri, 5 Jun
ONT
Ontario
SEA
Seattle
S$316 Return, found 5 days ago
S$316
Return
found 5 days ago
Select Delta flight, departing Tue, 2 Jun from Ontario to Seattle, returning Fri, 5 Jun, priced at S$316 found 5 days ago
Delta
Mon, 1 Jun - Fri, 5 Jun
ONT
Ontario
SEA
Seattle
S$329 Return, found 5 days ago
S$329
Return
found 5 days ago
Select Delta flight, departing Mon, 1 Jun from Ontario to Seattle, returning Fri, 5 Jun, priced at S$329 found 5 days ago
Delta
Thu, 28 May - Wed, 10 Jun
ONT
Ontario
SEA
Seattle
S$342 Return, found 5 days ago
S$342
Return
found 5 days ago
Select Delta flight, departing Thu, 28 May from Ontario to Seattle, returning Wed, 10 Jun, priced at S$342 found 5 days ago
Delta
Sat, 30 May - Sun, 7 Jun
ONT
Ontario
SEA
Seattle
S$355 Return, found 5 days ago
S$355
Return
found 5 days ago
Select Delta flight, departing Sat, 30 May from Ontario to Seattle, returning Sun, 7 Jun, priced at S$355 found 5 days ago
United
Sat, 30 May - Sun, 7 Jun
ONT
Ontario
SEA
Seattle
S$392 Return, found 5 days ago
S$392
Return
found 5 days ago
Select United flight, departing Sat, 30 May from Ontario to Seattle, returning Sun, 7 Jun, priced at S$392 found 5 days ago
Alaska Airlines
Tue, 9 Jun - Thu, 18 Jun
ONT
Ontario
SEA
Seattle
S$393 Return, found 5 days ago
S$393
Return
found 5 days ago
Select Alaska Airlines flight, departing Tue, 9 Jun from Ontario to Seattle, returning Thu, 18 Jun, priced at S$393 found 5 days ago
American Airlines
Wed, 29 Jul - Tue, 18 Aug
ONT
Ontario
SEA
Seattle
S$532 Return, found 2 days ago
S$532
Return
found 2 days ago
Select American Airlines flight, departing Wed, 29 Jul from Ontario to Seattle, returning Tue, 18 Aug, priced at S$532 found 2 days ago

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

May is typically the cheapest month to fly

From S$128 - S$263 per traveller.

Frequently asked questions

How much is a flight from Ontario Airport to Sea-Tac Airport?
If you're travelling between Ontario Airport and Seattle - Tacoma Intl. Airport (SEA), round-trip journeys start from S$253. 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 kilometres. 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 travellers 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.

Travel information

Origin airport
Ontario Intl. Airport
Destination airport
Seattle - Tacoma Intl.
Return price
S$252
Distance
1530 km
Average flight time
2 hours 58 mins

Book with confidence

Perfect flights from Ontario Intl. Airport to Seattle

Your Journey from Ontario Intl. Airport to Seattle

Start your unforgettable journey with Expedia. Our broad selection of flights from Ontario Intl. Airport to Seattle caters to every travel need. Whether you're yearning for a romantic escape, a solo adventure, or a cultural immersion, we've got you covered.
 

Choosing Your Ideal Flight

With Expedia, you have access to a wide range of airlines, including Delta, United, American Airlines, Alaska Airlines. Our selection of flights from Ontario Intl. Airport to Seattle - Tacoma Intl. caters to every traveler's requirements, ensuring your journey aligns with your schedule. With options from 20 airlines, you're bound to find the perfect flight.
 

Maximizing Value with Ontario Intl. Airport to Seattle Flights

Experience the joy of finding cheap flights from Ontario Intl. Airport to Seattle - Tacoma Intl. that fit your budget. Keep an eye out for our special deals and discounts, and check our flexible one-way fares from S$153 and roundtrip prices from S$253*.
 

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Experience the Vibrant Seattle

Picture yourself stepping off the plane in Seattle and immersing yourself in the unique atmosphere of . From local markets to cultural festivals, each city offers its distinct charm. Make the most of your trip by exploring local attractions and indulging in the local cuisine. With Expedia, explore all this and more, tailored to your budget.
 

Added Convenience on Your Ontario Intl. Airport to Seattle Flight

Traveling with Expedia is more than just a flight. We offer details about in-flight amenities, baggage policies, and more to ensure a smooth and hassle-free journey. Choose from our variety of airlines and embark on a memorable journey from Ontario Intl. Airport to Seattle.
 

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With Expedia, your adventure extends beyond the flight. Explore Seattle at your own pace by renting a car or booking a hotel. Discover hidden gems off the beaten path and create unforgettable memories.
 

Book Your Flight from Ontario Intl. Airport to Seattle with Confidence

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*Note: Prices may vary based on availability and are subject to change.
Perfect flights from Ontario Intl. Airport to Seattle

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