฿3,910 Cheap Flights from Seattle (SEA) to Ontario (ONT)

View ฿3,910 flight on Fri, 14 Nov 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 (SEA) to Ontario (ONT)

Prices were available within the past 7 days and start at ฿3,910 for one-way flights and ฿5,815 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Wed, 12 Nov - Sat, 15 Nov
SEA
Seattle
ONT
Ontario
฿5,815 Return, found 7 hours ago
฿5,815
Return
found 7 hours ago
Select Delta flight, departing Wed, 12 Nov from Seattle to Ontario, returning Sat, 15 Nov, priced at ฿5,815 found 7 hours ago
Alaska Airlines
Wed, 12 Nov - Thu, 20 Nov
SEA
Seattle
ONT
Ontario
฿5,870 Return, found 7 hours ago
฿5,870
Return
found 7 hours ago
Select Alaska Airlines flight, departing Wed, 12 Nov from Seattle to Ontario, returning Thu, 20 Nov, priced at ฿5,870 found 7 hours ago
Delta
Thu, 13 Nov - Sat, 15 Nov
SEA
Seattle
ONT
Ontario
฿6,145 Return, found 7 hours ago
฿6,145
Return
found 7 hours ago
Select Delta flight, departing Thu, 13 Nov from Seattle to Ontario, returning Sat, 15 Nov, priced at ฿6,145 found 7 hours ago
Delta
Thu, 13 Nov - Thu, 20 Nov
SEA
Seattle
ONT
Ontario
฿6,475 Return, found 7 hours ago
฿6,475
Return
found 7 hours ago
Select Delta flight, departing Thu, 13 Nov from Seattle to Ontario, returning Thu, 20 Nov, priced at ฿6,475 found 7 hours ago
Delta
Fri, 14 Nov - Sun, 16 Nov
SEA
Seattle
ONT
Ontario
฿6,500 Return, found 5 days ago
฿6,500
Return
found 5 days ago
Select Delta flight, departing Fri, 14 Nov from Seattle to Ontario, returning Sun, 16 Nov, priced at ฿6,500 found 5 days ago
Delta
Sat, 8 Nov - Wed, 12 Nov
SEA
Seattle
ONT
Ontario
฿7,780 Return, found 7 hours ago
฿7,780
Return
found 7 hours ago
Select Delta flight, departing Sat, 8 Nov from Seattle to Ontario, returning Wed, 12 Nov, priced at ฿7,780 found 7 hours ago
United
Fri, 14 Nov - Sun, 16 Nov
SEA
Seattle
ONT
Ontario
฿7,985 Return, found 5 days ago
฿7,985
Return
found 5 days ago
Select United flight, departing Fri, 14 Nov from Seattle to Ontario, returning Sun, 16 Nov, priced at ฿7,985 found 5 days ago
Delta
Sat, 8 Nov - Sun, 16 Nov
SEA
Seattle
ONT
Ontario
฿8,105 Return, found 7 hours ago
฿8,105
Return
found 7 hours ago
Select Delta flight, departing Sat, 8 Nov from Seattle to Ontario, returning Sun, 16 Nov, priced at ฿8,105 found 7 hours ago
Hawaiian Airlines
Sat, 25 Oct - Mon, 27 Oct
SEA
Seattle
ONT
Ontario
฿15,625 Return, found 1 day ago
฿15,625
Return
found 1 day ago
Select Hawaiian Airlines flight, departing Sat, 25 Oct from Seattle to Ontario, returning Mon, 27 Oct, priced at ฿15,625 found 1 day ago
American Airlines
Fri, 14 Nov - Sun, 16 Nov
SEA
Seattle
ONT
Ontario
฿17,355 Return, found 5 days ago
฿17,355
Return
found 5 days ago
Select American Airlines flight, departing Fri, 14 Nov from Seattle to Ontario, returning Sun, 16 Nov, priced at ฿17,355 found 5 days ago

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

November is typically the cheapest month to fly

From ฿2,563 - ฿7,498 per traveller.

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 ฿5,815. 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.

Travel information

Origin airport
Seattle - Tacoma Intl.
Destination airport
Los Angeles - Ontario Intl.
Return price
฿5,815
Distance
1530 km
Average flight time
2 hours 41 mins

Book with confidence

Perfect flights from Seattle to Ontario

Embark on an unforgettable journey without breaking the bank with Expedia's incredible deals on cheap flights from Seattle to Ontario. Whether you're aching for a romantic escape with your partner, craving an adventurous solo expedition, or yearning to immerse yourself in the local history and culture, we've got you covered.
 
Picture yourself strolling through the streets of , surrounded by breathtaking architecture and absorbing the vibrant atmosphere of this captivating city. Indulge in the mouth-watering local specialties, from tantalizing street food to exquisite fine dining. With Expedia, you can experience all of this and more, without sacrificing your budget.
 
Our flexible Seattle - Tacoma Intl. to Los Angeles - Ontario Intl. ticket options cater to your travel preferences, with incredible one-way fares from ฿3,910 and roundtrip prices from ฿5,815. Whether you're planning a short city break or a longer adventure, our dynamic pricing ensures that you find the best deals for your journey.
 
But the magic doesn't stop there. Expedia offers a range of partner services to enhance your trip. Rent a car at Los Angeles - Ontario Intl. and explore and its surrounding areas at your own pace. Discover hidden gems off the beaten path, and create unforgettable memories. We also provide a handpicked selection of accommodations, from charming bed and breakfasts to luxury hotels, ensuring that you have a comfortable and memorable stay.
 
Planning your next great adventure is a breeze with Expedia. Our user-friendly platform, unbeatable prices, and round-the-clock customer support are designed to make your travel experience seamless and stress-free. So, why wait? Book your to travel arrangements today and embark on the journey of a lifetime in Ontario.
Perfect flights from Seattle to Ontario

Explore a world of travel with Expedia

Ontario Airports

Los Angeles

Seattle to Los Angeles Intl.
฿5,845.00

Burbank

Orange County

Seattle Airports

Seattle Paine Field Intl. Airport

*Available to Expedia members.