$139 Cheap United flights Ontario (ONT) to Seattle (SEA)

View $139 flight on Sun, Apr 26, 2026Opens in a new window

$139 Cheap United flights Ontario (ONT) to Seattle (SEA)

Prices were available within the past 7 days and start at $139 for one-way flights and $337 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Sat, Aug 15 - Tue, Aug 25
ONT
Ontario
SEA
Seattle
$337 Roundtrip, found 1 day ago
$337
Roundtrip
found 1 day ago
Select United flight, departing Sat, Aug 15 from Ontario to Seattle, returning Tue, Aug 25, priced at $337 found 1 day ago

Alternative airports near Seattle

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Seattle - Tacoma Intl. SEA. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $191
SEA
Seattle - Tacoma Intl.
Cheapest
Average driving time to city center20 min
Flights from $191

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

November is typically the cheapest month to fly

From $79 - $250 per traveler.

Travel information

Origin airport
Los Angeles - Ontario Intl.
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Popular airline
Delta
Distance
1530 km
Average flight time
3 hours 12 mins

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