$84 Cheap Frontier Airlines flights Ontario (ONT) to Seattle (SEA)

View $84 flight on Wed, Aug 6, 2025Opens in a new window

$84 Cheap Frontier Airlines flights Ontario (ONT) to Seattle (SEA)

Prices were available within the past 7 days and start at $84 for one-way flights and $149 for roundtrip, for the period specified. Prices and availability are subject to change. Additional terms apply.
Frontier Airlines
Wed, Aug 6 - Sat, Aug 16
ONT
Ontario
SEA
Seattle
$149
Roundtrip
Found 2 days ago
Select Frontier Airlines flight, departing Wed, Aug 6 from Ontario to Seattle, returning Sat, Aug 16, priced at $149 Found 2 days ago
Frontier Airlines
Wed, Aug 6 - Tue, Aug 19
ONT
Ontario
SEA
Seattle
$168
Roundtrip
Found 2 days ago
Select Frontier Airlines flight, departing Wed, Aug 6 from Ontario to Seattle, returning Tue, Aug 19, priced at $168 Found 2 days ago
Frontier Airlines
Wed, Aug 6 - Sat, Aug 16
ONT
Ontario
SEA
Seattle
$173
Roundtrip
Found 2 days ago
Select Frontier Airlines flight, departing Wed, Aug 6 from Ontario to Seattle, returning Sat, Aug 16, priced at $173 Found 2 days ago
Frontier Airlines
Mon, Aug 4 - Tue, Aug 19
ONT
Ontario
SEA
Seattle
$178
Roundtrip
Found 2 days ago
Select Frontier Airlines flight, departing Mon, Aug 4 from Ontario to Seattle, returning Tue, Aug 19, priced at $178 Found 2 days ago
Frontier Airlines
Mon, Aug 4 - Thu, Aug 14
ONT
Ontario
SEA
Seattle
$188
Roundtrip
Found 2 days ago
Select Frontier Airlines flight, departing Mon, Aug 4 from Ontario to Seattle, returning Thu, Aug 14, priced at $188 Found 2 days ago
Frontier Airlines
Sun, Aug 3 - Tue, Aug 19
ONT
Ontario
SEA
Seattle
$193
Roundtrip
Found 2 days ago
Select Frontier Airlines flight, departing Sun, Aug 3 from Ontario to Seattle, returning Tue, Aug 19, priced at $193 Found 2 days ago
Flights from Ontario (ONT) to Seattle (SEA)
Origin airport
Los Angeles - Ontario Intl.
Destination airport
Seattle - Tacoma Intl.
Distance
1530 km
Average flight time
2 hours 46 mins