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 $278 round trip and CA $168 one way. Prices and availability subject to change. Additional terms may apply.

Wed, Apr 15 - Tue, Apr 21
ONT
Ontario
SEA
Seattle
CA $278 Roundtrip, found 3 days ago
CA $278
Roundtrip
found 3 days ago
Select Alaska Airlines flight, departing Wed, Apr 15 from Ontario to Seattle, returning Tue, Apr 21, priced at CA $278 found 3 days ago
Wed, Apr 15 - Tue, Apr 21
ONT
Ontario
SEA
Seattle
CA $282 Roundtrip, found 3 days ago
CA $282
Roundtrip
found 3 days ago
Select Alaska Airlines flight, departing Wed, Apr 15 from Ontario to Seattle, returning Tue, Apr 21, priced at CA $282 found 3 days ago
Thu, Apr 16 - Wed, Apr 22
ONT
Ontario
SEA
Seattle
CA $291 Roundtrip, found 6 days ago
CA $291
Roundtrip
found 6 days ago
Select Alaska Airlines flight, departing Thu, Apr 16 from Ontario to Seattle, returning Wed, Apr 22, priced at CA $291 found 6 days ago
Thu, Apr 16 - Wed, Apr 22
ONT
Ontario
SEA
Seattle
CA $320 Roundtrip, found 6 days ago
CA $320
Roundtrip
found 6 days ago
Select Alaska Airlines flight, departing Thu, Apr 16 from Ontario to Seattle, returning Wed, Apr 22, priced at CA $320 found 6 days ago
Thu, Apr 16 - Wed, Apr 22
ONT
Ontario
SEA
Seattle
CA $325 Roundtrip, found 6 days ago
CA $325
Roundtrip
found 6 days ago
Select Alaska Airlines flight, departing Thu, Apr 16 from Ontario to Seattle, returning Wed, Apr 22, priced at CA $325 found 6 days ago
Sat, Apr 25 - Sun, Apr 26
ONT
Ontario
SEA
Seattle
CA $334 Roundtrip, found 6 days ago
CA $334
Roundtrip
found 6 days ago
Select Alaska Airlines flight, departing Sat, Apr 25 from Ontario to Seattle, returning Sun, Apr 26, priced at CA $334 found 6 days ago
Wed, Apr 15 - Tue, Apr 21
ONT
Ontario
SEA
Seattle
CA $338 Roundtrip, found 3 days ago
CA $338
Roundtrip
found 3 days ago
Select Alaska Airlines flight, departing Wed, Apr 15 from Ontario to Seattle, returning Tue, Apr 21, priced at CA $338 found 3 days ago
Wed, Apr 15 - Tue, Apr 21
ONT
Ontario
SEA
Seattle
CA $355 Roundtrip, found 3 days ago
CA $355
Roundtrip
found 3 days ago
Select Alaska Airlines flight, departing Wed, Apr 15 from Ontario to Seattle, returning Tue, Apr 21, priced at CA $355 found 3 days ago
Wed, Apr 15 - Tue, Apr 21
ONT
Ontario
SEA
Seattle
CA $361 Roundtrip, found 3 days ago
CA $361
Roundtrip
found 3 days ago
Select Alaska Airlines flight, departing Wed, Apr 15 from Ontario to Seattle, returning Tue, Apr 21, priced at CA $361 found 3 days ago
Thu, Apr 16 - Wed, Apr 22
ONT
Ontario
SEA
Seattle
CA $368 Roundtrip, found 6 days ago
CA $368
Roundtrip
found 6 days ago
Select Alaska Airlines flight, departing Thu, Apr 16 from Ontario to Seattle, returning Wed, Apr 22, priced at CA $368 found 6 days 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.

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*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.