S$166 Cheap Flights from Seattle to Ontario

View S$166 flight on Mon, 22 Dec, 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$166 for one-way flights and S$255 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Sun, 19 Oct - Sun, 2 Nov
SEA
Seattle
ONT
Ontario
S$255 Return, found 14 hours ago
S$255
Return
found 14 hours ago
Select Delta flight, departing Sun, 19 Oct from Seattle to Ontario, returning Sun, 2 Nov, priced at S$255 found 14 hours ago
Delta
Sat, 28 Jun - Sun, 13 Jul
SEA
Seattle
ONT
Ontario
S$331 Return, found 2 days ago
S$331
Return
found 2 days ago
Select Delta flight, departing Sat, 28 Jun from Seattle to Ontario, returning Sun, 13 Jul, priced at S$331 found 2 days ago
Delta
Mon, 21 Jul - Mon, 28 Jul
SEA
Seattle
ONT
Ontario
S$332 Return, found 1 day ago
S$332
Return
found 1 day ago
Select Delta flight, departing Mon, 21 Jul from Seattle to Ontario, returning Mon, 28 Jul, priced at S$332 found 1 day ago
Delta
Tue, 24 Jun - Sun, 13 Jul
SEA
Seattle
ONT
Ontario
S$344 Return, found 2 days ago
S$344
Return
found 2 days ago
Select Delta flight, departing Tue, 24 Jun from Seattle to Ontario, returning Sun, 13 Jul, priced at S$344 found 2 days ago
Delta
Mon, 21 Jul - Mon, 28 Jul
SEA
Seattle
ONT
Ontario
S$351 Return, found 1 day ago
S$351
Return
found 1 day ago
Select Delta flight, departing Mon, 21 Jul from Seattle to Ontario, returning Mon, 28 Jul, priced at S$351 found 1 day ago
Delta
Wed, 11 Jun - Wed, 2 Jul
SEA
Seattle
ONT
Ontario
S$370 Return, found 2 days ago
S$370
Return
found 2 days ago
Select Delta flight, departing Wed, 11 Jun from Seattle to Ontario, returning Wed, 2 Jul, priced at S$370 found 2 days ago
Delta
Mon, 21 Jul - Mon, 28 Jul
SEA
Seattle
ONT
Ontario
S$384 Return, found 1 day ago
S$384
Return
found 1 day ago
Select Delta flight, departing Mon, 21 Jul from Seattle to Ontario, returning Mon, 28 Jul, priced at S$384 found 1 day ago
Delta
Mon, 21 Jul - Mon, 28 Jul
SEA
Seattle
ONT
Ontario
S$390 Return, found 1 day ago
S$390
Return
found 1 day ago
Select Delta flight, departing Mon, 21 Jul from Seattle to Ontario, returning Mon, 28 Jul, priced at S$390 found 1 day ago
Delta
Mon, 21 Jul - Mon, 28 Jul
SEA
Seattle
ONT
Ontario
S$403 Return, found 1 day ago
S$403
Return
found 1 day ago
Select Delta flight, departing Mon, 21 Jul from Seattle to Ontario, returning Mon, 28 Jul, priced at S$403 found 1 day ago
Delta
Wed, 11 Jun - Thu, 3 Jul
SEA
Seattle
ONT
Ontario
S$409 Return, found 2 days ago
S$409
Return
found 2 days ago
Select Delta flight, departing Wed, 11 Jun from Seattle to Ontario, returning Thu, 3 Jul, priced at S$409 found 2 days ago
Seattle to Ontario route information
Origin airport
Seattle - Tacoma Intl.
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
American Airlines, Delta, United
Return price
S$255
Distance
1530 km
Average flight time
2 hours 38 mins

Perfect flights from Seattle to Ontario

Your Journey from Seattle to Ontario

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

Experience the joy of finding cheap flights from Seattle - Tacoma Intl. to Los Angeles - Ontario Intl. that fit your budget. Keep an eye out for our special deals and discounts, and check our flexible one-way fares from S$166 and roundtrip prices from S$255*.
 

Pre-Flight Essentials

Ensure a smooth journey from Seattle to Ontario 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 Ontario

Picture yourself stepping off the plane in Ontario 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 Seattle to Ontario 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 Seattle to Ontario.
 

Beyond the Flight – Exploring Ontario

With Expedia, your adventure extends beyond the flight. Explore Ontario 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 Seattle to Ontario 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 Seattle to Ontario with confidence. Book your travel arrangements with Expedia today.
 
*Note: Prices may vary based on availability and are subject to change.

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$255. 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.

Explore a world of travel with Expedia

Ontario Airports

Los Angeles

Seattle to Los Angeles Intl.
S$228.60

Orange County

Seattle to John Wayne
S$332.00

Burbank

Seattle to Hollywood Burbank
S$537.40

Long Beach

Seattle Airports

Seattle Paine Field Intl. Airport

*Available to Expedia members.