$111 Cheap Frontier Airlines flights Seattle (SEA) to Ontario (ONT)

View $111 flight on Thu, Jan 29, 2026Opens in a new window

$111 Cheap Frontier Airlines flights Seattle (SEA) to Ontario (ONT)

Prices were available within the past 7 days and start at $111 for one-way flights and $190 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Thu, Jan 29 - Sun, Feb 1
SEA
Seattle
ONT
Ontario
$190 Roundtrip, found 2 days ago
$190
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Thu, Jan 29 from Seattle to Ontario, returning Sun, Feb 1, priced at $190 found 2 days ago
Frontier Airlines
Mon, Jan 5 - Thu, Jan 8
SEA
Seattle
ONT
Ontario
$276 Roundtrip, found 2 days ago
$276
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Mon, Jan 5 from Seattle to Ontario, returning Thu, Jan 8, priced at $276 found 2 days ago

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

October is typically the cheapest month to fly

From $79 - $160 per traveler.

Alternative airports near Ontario

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

Select flight to John Wayne SNA. Cheapest option available. Average driving time to city center is 42 minutes. Flights from $268
SNA
John Wayne
Cheapest
Average driving time to city center42 min
Flights from $268
Flights from Seattle (SEA) to Ontario (ONT)
Origin airport
Seattle - Tacoma Intl.
Destination airport
Los Angeles - Ontario Intl.
Distance
1530 km
Average flight time
2 hours 39 mins