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

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

Prices were available within the past 7 days and start at for one-way flights and $210 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Fri, Feb 6 - Fri, Feb 20

ONT

Ontario

STL

St. Louis

$210 Roundtrip, found 19 hours ago

$210

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Fri, Feb 6 from Ontario to St. Louis, returning Fri, Feb 20, priced at $210 found 19 hours ago

Fri, Feb 20 - Sat, Mar 7

ONT

Ontario

STL

St. Louis

$220 Roundtrip, found 19 hours ago

$220

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Fri, Feb 20 from Ontario to St. Louis, returning Sat, Mar 7, priced at $220 found 19 hours ago

Mon, Feb 9 - Wed, Feb 25

ONT

Ontario

STL

St. Louis

$230 Roundtrip, found 19 hours ago

$230

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Mon, Feb 9 from Ontario to St. Louis, returning Wed, Feb 25, priced at $230 found 19 hours ago

Fri, Feb 20 - Fri, Mar 6

ONT

Ontario

STL

St. Louis

$270 Roundtrip, found 19 hours ago

$270

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Fri, Feb 20 from Ontario to St. Louis, returning Fri, Mar 6, priced at $270 found 19 hours ago

Wed, Mar 4 - Mon, Mar 16

ONT

Ontario

STL

St. Louis

$280 Roundtrip, found 19 hours ago

$280

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Wed, Mar 4 from Ontario to St. Louis, returning Mon, Mar 16, priced at $280 found 19 hours ago

Fri, Jan 30 - Wed, Feb 18

ONT

Ontario

STL

St. Louis

$310 Roundtrip, found 22 hours ago

$310

Roundtrip

found 22 hours ago

Select Frontier Airlines flight, departing Fri, Jan 30 from Ontario to St. Louis, returning Wed, Feb 18, priced at $310 found 22 hours ago

Sat, Feb 7 - Wed, Feb 18

ONT

Ontario

STL

St. Louis

$320 Roundtrip, found 19 hours ago

$320

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Sat, Feb 7 from Ontario to St. Louis, returning Wed, Feb 18, priced at $320 found 19 hours ago

Sat, Feb 21 - Fri, Mar 6

ONT

Ontario

STL

St. Louis

$330 Roundtrip, found 19 hours ago

$330

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Sat, Feb 21 from Ontario to St. Louis, returning Fri, Mar 6, priced at $330 found 19 hours ago

Sat, Feb 28 - Sat, Mar 14

ONT

Ontario

STL

St. Louis

$370 Roundtrip, found 19 hours ago

$370

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Sat, Feb 28 from Ontario to St. Louis, returning Sat, Mar 14, priced at $370 found 19 hours ago

Sat, Feb 28 - Fri, Mar 13

ONT

Ontario

STL

St. Louis

$440 Roundtrip, found 19 hours ago

$440

Roundtrip

found 19 hours ago

Select Frontier Airlines flight, departing Sat, Feb 28 from Ontario to St. Louis, returning Fri, Mar 13, priced at $440 found 19 hours ago