$85 Cheap Frontier Airlines flights Ontario (ONT) to St. Louis (STL)

$85 Cheap Frontier Airlines flights Ontario (ONT) to St. Louis (STL)

Prices were available within the past 7 days and start at $85 for one-way flights and $215 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Sat, May 16 - Wed, May 20

ONT

Ontario

STL

St. Louis

$215 Roundtrip, found 1 day ago

$215

Roundtrip

found 1 day ago

Select Frontier Airlines flight, departing Sat, May 16 from Ontario to St. Louis, returning Wed, May 20, priced at $215 found 1 day ago

Sat, May 16 - Sun, May 17

ONT

Ontario

STL

St. Louis

$240 Roundtrip, found 1 day ago

$240

Roundtrip

found 1 day ago

Select Frontier Airlines flight, departing Sat, May 16 from Ontario to St. Louis, returning Sun, May 17, priced at $240 found 1 day ago

Wed, May 13 - Sun, May 17

ONT

Ontario

STL

St. Louis

$280 Roundtrip, found 1 day ago

$280

Roundtrip

found 1 day ago

Select Frontier Airlines flight, departing Wed, May 13 from Ontario to St. Louis, returning Sun, May 17, priced at $280 found 1 day ago

Sat, May 16 - Mon, May 18

ONT

Ontario

STL

St. Louis

$291 Roundtrip, found 1 day ago

$291

Roundtrip

found 1 day ago

Select Frontier Airlines flight, departing Sat, May 16 from Ontario to St. Louis, returning Mon, May 18, priced at $291 found 1 day ago

Sat, May 16 - Wed, Jun 3

ONT

Ontario

STL

St. Louis

$307 Roundtrip, found 4 days ago

$307

Roundtrip

found 4 days ago

Select Frontier Airlines flight, departing Sat, May 16 from Ontario to St. Louis, returning Wed, Jun 3, priced at $307 found 4 days ago

Tue, May 12 - Mon, May 18

ONT

Ontario

STL

St. Louis

$316 Roundtrip, found 1 day ago

$316

Roundtrip

found 1 day ago

Select Frontier Airlines flight, departing Tue, May 12 from Ontario to St. Louis, returning Mon, May 18, priced at $316 found 1 day ago