S$89 Cheap Flights from Ontario to Seattle

View S$89 flight on Thu, 9 Apr, 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 to Seattle (ONT-SEA)

Prices were available within the past 7 days and start at S$89 for one-way flights and S$213 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 24 Mar - Tue, 7 Apr
ONT
Ontario
SEA
Seattle
S$213 Return, found 1 day ago
S$213
Return
found 1 day ago
Select Delta flight, departing Tue, 24 Mar from Ontario to Seattle, returning Tue, 7 Apr, priced at S$213 found 1 day ago
Delta
Tue, 24 Mar - Sun, 12 Apr
ONT
Ontario
SEA
Seattle
S$250 Return, found 1 day ago
S$250
Return
found 1 day ago
Select Delta flight, departing Tue, 24 Mar from Ontario to Seattle, returning Sun, 12 Apr, priced at S$250 found 1 day ago
Delta
Mon, 9 Mar - Mon, 16 Mar
ONT
Ontario
SEA
Seattle
S$263 Return, found 2 days ago
S$263
Return
found 2 days ago
Select Delta flight, departing Mon, 9 Mar from Ontario to Seattle, returning Mon, 16 Mar, priced at S$263 found 2 days ago
Delta
Sun, 19 Apr - Thu, 7 May
ONT
Ontario
SEA
Seattle
S$289 Return, found 1 day ago
S$289
Return
found 1 day ago
Select Delta flight, departing Sun, 19 Apr from Ontario to Seattle, returning Thu, 7 May, priced at S$289 found 1 day ago
Delta
Sun, 8 Mar - Wed, 25 Mar
ONT
Ontario
SEA
Seattle
S$314 Return, found 1 day ago
S$314
Return
found 1 day ago
Select Delta flight, departing Sun, 8 Mar from Ontario to Seattle, returning Wed, 25 Mar, priced at S$314 found 1 day ago
Alaska Airlines
Thu, 26 Mar - Wed, 8 Apr
ONT
Ontario
SEA
Seattle
S$320 Return, found 1 day ago
S$320
Return
found 1 day ago
Select Alaska Airlines flight, departing Thu, 26 Mar from Ontario to Seattle, returning Wed, 8 Apr, priced at S$320 found 1 day ago
Delta
Tue, 23 Jun - Sat, 27 Jun
ONT
Ontario
SEA
Seattle
S$327 Return, found 2 days ago
S$327
Return
found 2 days ago
Select Delta flight, departing Tue, 23 Jun from Ontario to Seattle, returning Sat, 27 Jun, priced at S$327 found 2 days ago
Alaska Airlines
Mon, 29 Jun - Tue, 30 Jun
ONT
Ontario
SEA
Seattle
S$339 Return, found 2 days ago
S$339
Return
found 2 days ago
Select Alaska Airlines flight, departing Mon, 29 Jun from Ontario to Seattle, returning Tue, 30 Jun, priced at S$339 found 2 days ago
United
Mon, 9 Mar - Mon, 16 Mar
ONT
Ontario
SEA
Seattle
S$491 Return, found 2 days ago
S$491
Return
found 2 days ago
Select United flight, departing Mon, 9 Mar from Ontario to Seattle, returning Mon, 16 Mar, priced at S$491 found 2 days ago
American Airlines
Fri, 26 Jun - Sun, 28 Jun
ONT
Ontario
SEA
Seattle
S$1,262 Return, found 1 day ago
S$1,262
Return
found 1 day ago
Select American Airlines flight, departing Fri, 26 Jun from Ontario to Seattle, returning Sun, 28 Jun, priced at S$1,262 found 1 day ago

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

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From S$103 - S$326 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$213. 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
Los Angeles - Ontario Intl.
Destination airport
Seattle - Tacoma Intl.
Return price
S$212
Distance
1530 km
Average flight time
2 hours 56 mins

Book with confidence

Perfect flights from Ontario to Seattle

Your Journey from Ontario to Seattle

Start your unforgettable journey with Expedia. Our broad selection of flights from Ontario 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, Alaska Airlines, United, American Airlines. Our selection of flights from Los Angeles - Ontario Intl. 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 to Seattle Flights

Experience the joy of finding cheap flights from Los Angeles - Ontario Intl. 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$89 and roundtrip prices from S$213*.
 

Pre-Flight Essentials

Ensure a smooth journey from Ontario to Seattle with Expedia. From information about check-in times and in-flight amenities to guidance on baggage policies, we provide all the essentials to prepare you for your flight.
 

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 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 to Seattle.
 

Beyond the Flight – Exploring Seattle

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 to Seattle with Confidence

Planning your next great adventure is a breeze with Expedia. Our user-friendly platform, unbeatable prices, and round-the-clock customer support make your travel experience seamless and stress-free. Embark on your journey from Ontario to Seattle with confidence. Book your travel arrangements with Expedia today.
 
*Note: Prices may vary based on availability and are subject to change.
Perfect flights from Ontario to Seattle

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