$116 Cheap Frontier Airlines flights St. Louis (STL) to Ontario Intl. Airport (ONT)

$116 Cheap Frontier Airlines flights St. Louis (STL) to Ontario Intl. Airport (ONT)

Prices were available within the past 7 days and start at $116 for one-way flights and $240 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Wed, Sep 16 - Thu, Sep 17

STL

St. Louis

ONT

Ontario

$240 Roundtrip, found 6 days ago

$240

Roundtrip

found 6 days ago

Select Frontier Airlines flight, departing Wed, Sep 16 from St. Louis to Ontario, returning Thu, Sep 17, priced at $240 found 6 days ago

Tue, Jun 23 - Wed, Jul 8

STL

St. Louis

ONT

Ontario

$280 Roundtrip, found 10 hours ago

$280

Roundtrip

found 10 hours ago

Select Frontier Airlines flight, departing Tue, Jun 23 from St. Louis to Ontario, returning Wed, Jul 8, priced at $280 found 10 hours ago

Tue, Jun 23 - Sat, Jul 11

STL

St. Louis

ONT

Ontario

$294 Roundtrip, found 10 hours ago

$294

Roundtrip

found 10 hours ago

Select Frontier Airlines flight, departing Tue, Jun 23 from St. Louis to Ontario, returning Sat, Jul 11, priced at $294 found 10 hours ago

Tue, Jun 23 - Thu, Jul 9

STL

St. Louis

ONT

Ontario

$299 Roundtrip, found 10 hours ago

$299

Roundtrip

found 10 hours ago

Select Frontier Airlines flight, departing Tue, Jun 23 from St. Louis to Ontario, returning Thu, Jul 9, priced at $299 found 10 hours ago

Tue, Jun 2 - Wed, Jun 17

STL

St. Louis

ONT

Ontario

$300 Roundtrip, found 10 hours ago

$300

Roundtrip

found 10 hours ago

Select Frontier Airlines flight, departing Tue, Jun 2 from St. Louis to Ontario, returning Wed, Jun 17, priced at $300 found 10 hours ago

Sat, Jun 27 - Sat, Jul 11

STL

St. Louis

ONT

Ontario

$308 Roundtrip, found 10 hours ago

$308

Roundtrip

found 10 hours ago

Select Frontier Airlines flight, departing Sat, Jun 27 from St. Louis to Ontario, returning Sat, Jul 11, priced at $308 found 10 hours ago