CA $109 Cheap Flights from Ontario (ONT) to Seattle (SEA)

View CA $109 flight on Sat, May 17, 2025Opens in a new window

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Cheap flights from Ontario (ONT) to Seattle (SEA)

Prices were available within the past 7 days and start at CA $109 for one-way flights and CA $151 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Thu., May 15 - Sat., May 24
ONT
Ontario
SEA
Seattle
CA $151 Roundtrip, found 6 days ago
CA $151
Roundtrip
found 6 days ago
Select Frontier Airlines flight, departing Thu., May 15 from Ontario to Seattle, returning Sat., May 24, priced at CA $151 found 6 days ago
Frontier Airlines
Thu., May 15 - Mon., May 19
ONT
Ontario
SEA
Seattle
CA $165 Roundtrip, found 6 days ago
CA $165
Roundtrip
found 6 days ago
Select Frontier Airlines flight, departing Thu., May 15 from Ontario to Seattle, returning Mon., May 19, priced at CA $165 found 6 days ago
Alaska Airlines
Tue., Jun. 10 - Tue., Jun. 17
ONT
Ontario
SEA
Seattle
CA $217 Roundtrip, found 10 hours ago
CA $217
Roundtrip
found 10 hours ago
Select Alaska Airlines flight, departing Tue., Jun. 10 from Ontario to Seattle, returning Tue., Jun. 17, priced at CA $217 found 10 hours ago
Hawaiian Airlines
Tue., Jun. 10 - Tue., Jun. 17
ONT
Ontario
SEA
Seattle
CA $217 Roundtrip, found 20 hours ago
CA $217
Roundtrip
found 20 hours ago
Select Hawaiian Airlines flight, departing Tue., Jun. 10 from Ontario to Seattle, returning Tue., Jun. 17, priced at CA $217 found 20 hours ago
Alaska Airlines
Wed., May 14 - Sat., May 24
ONT
Ontario
SEA
Seattle
CA $217 Roundtrip, found 1 day ago
CA $217
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Wed., May 14 from Ontario to Seattle, returning Sat., May 24, priced at CA $217 found 1 day ago
Hawaiian Airlines
Tue., May 27 - Sat., May 31
ONT
Ontario
SEA
Seattle
CA $218 Roundtrip, found 4 days ago
CA $218
Roundtrip
found 4 days ago
Select Hawaiian Airlines flight, departing Tue., May 27 from Ontario to Seattle, returning Sat., May 31, priced at CA $218 found 4 days ago
Frontier Airlines
Sun., May 18 - Sat., May 24
ONT
Ontario
SEA
Seattle
CA $222 Roundtrip, found 6 days ago
CA $222
Roundtrip
found 6 days ago
Select Frontier Airlines flight, departing Sun., May 18 from Ontario to Seattle, returning Sat., May 24, priced at CA $222 found 6 days ago
Hawaiian Airlines
Wed., May 14 - Fri., May 16
ONT
Ontario
SEA
Seattle
CA $231 Roundtrip, found 2 hours ago
CA $231
Roundtrip
found 2 hours ago
Select Hawaiian Airlines flight, departing Wed., May 14 from Ontario to Seattle, returning Fri., May 16, priced at CA $231 found 2 hours ago
Delta
Sat., May 17 - Mon., May 19
ONT
Ontario
SEA
Seattle
CA $246 Roundtrip, found 1 day ago
CA $246
Roundtrip
found 1 day ago
Select Delta flight, departing Sat., May 17 from Ontario to Seattle, returning Mon., May 19, priced at CA $246 found 1 day ago
American Airlines
Sat., May 17 - Mon., May 19
ONT
Ontario
SEA
Seattle
CA $535 Roundtrip, found 1 day ago
CA $535
Roundtrip
found 1 day ago
Select American Airlines flight, departing Sat., May 17 from Ontario to Seattle, returning Mon., May 19, priced at CA $535 found 1 day ago
Flight from Ontario to Seattle (ONT - SEA) route information
Origin airport
Los Angeles - Ontario Intl.
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Hawaiian Airlines
Roundtrip price
CA $150
Distance
1530 km

Los Angeles to Seattle Flights

Ready for an adventure? Thought so! Prepare to see the sights when you book your trip from Los Angeles to Seattle with Expedia.ca. Whether you’re visiting for business or pleasure, we know how important it is to bring home travel stories. Maybe your tales will include the best dinner of your life, or the weirdest street art you saw in the city, or the concert that turned you into a fan of a new band. Whatever it is, your new favourite anecdote is right around the corner. Book your trip from ONT to SEA and begin your journey!

Getting a cheap deal on your trip sets the tone for the perfect holiday. And with Expedia.ca, you know you can travel from Los Angeles to Seattle on the cheap, with enough money left over for a stellar time in the city. That could mean more tours with the kids, more concerts with the spouse, more dessert amongst co-workers, or even front row seats to a sports game if you’re travelling solo. It’s your holiday! Make it great.

Travelling shouldn’t cost an arm and a leg before you even get to relax on the plane’s armrests. Count on Expedia.ca to get you the best discounts on flights from ONT to SEA. And remember this: You can also save big when you bundle. Add a hotel or car rental deal to your flight and witness those savings add up. Hey, more money for more souvenirs, right? Right! Pack your bags and we’ll see you on the route.

Combine your Seattle flight with a hotel and/or car rental for a package deal designed to save you even more money! Discover additional savings by booking in advance or find a last minute deal. There are tons of ways to save on your flights from with Expedia Canada. Use us as your top travel destination and have the confidence that you’re getting a bargain!

Frequently asked questions

How much is a flight from Ontario Airport to Sea-Tac Airport?
If you’re traveling between Ontario Airport and Seattle - Tacoma Intl. Airport (SEA), round-trip journeys start from CA $151. 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 kilometers. 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 travelers 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.

Explore a world of travel with Expedia

Ontario nearby Airports

Los Angeles

Los Angeles Intl. to Seattle
CA $136.10

Orange County

John Wayne to Seattle
CA $168.77

Burbank

Hollywood Burbank to Seattle
CA $216.50
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