Cheap Flights From Los Angeles - Ontario Intl. (ONT) To Seattle - Tacoma Intl. (SEA)

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Cheapest Flights from Ontario (ONT) to Seattle (SEA)

The cheapest flights to Seattle - Tacoma Intl. found within the past 7 days were CA $220 round trip and CA $126 one way. Prices and availability subject to change. Additional terms may apply.

Tue, Dec 16 - Sat, Jan 3
ONT
Ontario
SEA
Seattle
CA $220 Roundtrip, found 5 hours ago
CA $220
Roundtrip
found 5 hours ago
Select Alaska Airlines flight, departing Tue, Dec 16 from Ontario to Seattle, returning Sat, Jan 3, priced at CA $220 found 5 hours ago
Tue, Dec 16 - Mon, Jan 5
ONT
Ontario
SEA
Seattle
CA $234 Roundtrip, found 5 hours ago
CA $234
Roundtrip
found 5 hours ago
Select Delta flight, departing Tue, Dec 16 from Ontario to Seattle, returning Mon, Jan 5, priced at CA $234 found 5 hours ago
Tue, Dec 16 - Sat, Jan 3
ONT
Ontario
SEA
Seattle
CA $248 Roundtrip, found 5 hours ago
CA $248
Roundtrip
found 5 hours ago
Select Alaska Airlines flight, departing Tue, Dec 16 from Ontario to Seattle, returning Sat, Jan 3, priced at CA $248 found 5 hours ago
Tue, Dec 16 - Sat, Jan 3
ONT
Ontario
SEA
Seattle
CA $269 Roundtrip, found 5 hours ago
CA $269
Roundtrip
found 5 hours ago
Select Alaska Airlines flight, departing Tue, Dec 16 from Ontario to Seattle, returning Sat, Jan 3, priced at CA $269 found 5 hours ago
Thu, Dec 18 - Fri, Jan 2
ONT
Ontario
SEA
Seattle
CA $274 Roundtrip, found 5 hours ago
CA $274
Roundtrip
found 5 hours ago
Select Alaska Airlines flight, departing Thu, Dec 18 from Ontario to Seattle, returning Fri, Jan 2, priced at CA $274 found 5 hours ago
Fri, Dec 19 - Fri, Jan 2
ONT
Ontario
SEA
Seattle
CA $275 Roundtrip, found 5 hours ago
CA $275
Roundtrip
found 5 hours ago
Select Delta flight, departing Fri, Dec 19 from Ontario to Seattle, returning Fri, Jan 2, priced at CA $275 found 5 hours ago
Tue, Dec 16 - Mon, Jan 5
ONT
Ontario
SEA
Seattle
CA $280 Roundtrip, found 5 hours ago
CA $280
Roundtrip
found 5 hours ago
Select Delta flight, departing Tue, Dec 16 from Ontario to Seattle, returning Mon, Jan 5, priced at CA $280 found 5 hours ago
Tue, Dec 16 - Sat, Jan 3
ONT
Ontario
SEA
Seattle
CA $281 Roundtrip, found 5 hours ago
CA $281
Roundtrip
found 5 hours ago
Select Delta flight, departing Tue, Dec 16 from Ontario to Seattle, returning Sat, Jan 3, priced at CA $281 found 5 hours ago
Tue, Dec 16 - Mon, Jan 5
ONT
Ontario
SEA
Seattle
CA $283 Roundtrip, found 5 hours ago
CA $283
Roundtrip
found 5 hours ago
Select Alaska Airlines flight, departing Tue, Dec 16 from Ontario to Seattle, returning Mon, Jan 5, priced at CA $283 found 5 hours ago
Tue, Dec 16 - Mon, Jan 5
ONT
Ontario
SEA
Seattle
CA $287 Roundtrip, found 5 hours ago
CA $287
Roundtrip
found 5 hours ago
Select Alaska Airlines flight, departing Tue, Dec 16 from Ontario to Seattle, returning Mon, Jan 5, priced at CA $287 found 5 hours ago

Frequently asked questions

Are there direct flights from ONT to Sea-Tac Airport?
Multiple airlines offer direct flights from Los Angeles - Ontario Intl. Airport (ONT) to SEA. These include Alaska Airlines and Delta — start with them if you want to touch down at Seattle sooner rather than later.
What airlines fly from Ontario Airport to SEA?
If you need to get to Seattle from Ontario, there are a number of airlines with direct flights. One of the most popular is Alaska Airlines (AS), which offers 108 flights on this route each month. An alternative is Delta (DL), which offers 91 flights every month. The more air carriers you consider, the more likely you are to snap up a sensational deal.
What is the best day to buy a plane ticket?
Airfares offered on Friday tend to be the cheapest, according to flight demand on Travelocity.ca in 2021. Purchasing your airfares on a Thursday or Saturday can also provide better value, however our advice if you're looking to save money is to avoid booking on a Wednesday or Sunday. Our data shows that those two days have the highest ticket values on average, so keep this in mind if you're browsing flight deals.
What are the cheapest days to fly?
Frequent travellers may already know this, but earlier in the week is often the cheapest time to fly. Flights departing on a Monday are the cheapest of the week. Since flights towards the middle of the week tend to be more popular, this causes the prices to rise. This is why, on average, airfares booked on Travelocity.ca in 2021 were most expensive for Wednesday departures.
How far in advance can you book a flight?
Here's the deal: It is typically possible to start comparing international airfares on Travelocity.ca up to 12 months in advance. However, it does depend on the carrier as not all airlines release their prices that far out. According to our 2021 flight demand trends, last minute planners can still bag a bargain with some of the cheapest fares appearing 2-4 weeks prior to their travel dates.*According to flight demand on Travelocity.ca from January to December 2021. Savings are subject to change and may vary depending on selections made.
*Price based on the lowest price found within past 24 hours and based upon one night stay for two adults over the next thirty days. Prices and availability subject to change. Additional terms may apply.