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Flights from St. Louis to Ontario (STL to ONT)

Discover alternate routes & cheap one way flights from St. Louis to Ontario (STL to ONT) within a departure date range.

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  • USD 332
    Frontier Airlines
    8:45am - 1:24pm
    Tue Oct 10th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Oct 10th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Tue Oct 10th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 332
    Frontier Airlines
    8:45am - 1:24pm
    Tue Nov 7th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Nov 7th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Tue Nov 7th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Wed Nov 15th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Nov 15th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Wed Nov 15th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Tue Nov 14th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Nov 14th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Tue Nov 14th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Tue Oct 24th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Oct 24th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Tue Oct 24th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Tue Oct 17th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Oct 17th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Tue Oct 17th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Wed Nov 1st
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Nov 1st 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Wed Nov 1st 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Tue Oct 31st
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Oct 31st 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Tue Oct 31st 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Sat Nov 4th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Nov 4th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sat Nov 4th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Wed Oct 25th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Oct 25th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Wed Oct 25th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Sat Oct 21st
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Oct 21st 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sat Oct 21st 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Wed Oct 18th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Oct 18th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Wed Oct 18th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    8:45am - 1:24pm
    Sat Oct 28th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Oct 28th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sat Oct 28th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 339
    Frontier Airlines
    5:17pm - 12:31am
    Wed Nov 15th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Nov 15th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Wed Nov 15th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 339
    Frontier Airlines
    3:09pm - 12:31am
    Tue Nov 14th
    11h 22m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Nov 14th 2023 Frontier Airlines · F9 701 Depart at 3:09pm from St. Louis (STL) Fly for 2h 28m Arrive at 4:37pm in Denver (DEN)

    Layover in Denver for 6h 23m

    Tue Nov 14th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 340
    Frontier Airlines
    8:45am - 1:24pm
    Wed Nov 8th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Nov 8th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Wed Nov 8th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 340
    Frontier Airlines
    8:45am - 1:24pm
    Sat Nov 11th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Nov 11th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sat Nov 11th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 340
    Frontier Airlines
    5:17pm - 12:31am
    Sat Nov 11th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Nov 11th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Sat Nov 11th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 340
    Frontier Airlines
    5:17pm - 12:31am
    Wed Oct 11th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Oct 11th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Wed Oct 11th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 340
    Frontier Airlines
    5:17pm - 12:31am
    Wed Nov 8th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Nov 8th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Wed Nov 8th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 347
    Frontier Airlines
    5:17pm - 12:31am
    Wed Oct 18th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Oct 18th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Wed Oct 18th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 347
    Frontier Airlines
    5:17pm - 12:31am
    Wed Nov 1st
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Nov 1st 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Wed Nov 1st 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 347
    Frontier Airlines
    5:17pm - 12:31am
    Sat Nov 4th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Nov 4th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Sat Nov 4th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 347
    Frontier Airlines
    5:17pm - 12:31am
    Wed Oct 25th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Oct 25th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Wed Oct 25th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 347
    Frontier Airlines
    5:17pm - 12:31am
    Sat Oct 28th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Oct 28th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Sat Oct 28th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 353
    Frontier Airlines
    5:17pm - 12:31am
    Sat Oct 7th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Oct 7th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Sat Oct 7th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 356
    Frontier Airlines
    5:17pm - 12:31am
    Sat Oct 14th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Oct 14th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Sat Oct 14th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 412
    Frontier Airlines
    8:45am - 1:24pm
    Thu Oct 12th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Thu Oct 12th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Thu Oct 12th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 412
    Frontier Airlines
    8:45am - 1:24pm
    Mon Nov 6th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Nov 6th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Mon Nov 6th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 412
    Frontier Airlines
    6:50pm - 11:31pm
    Fri Nov 10th
    6h 41m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Nov 10th 2023 Frontier Airlines · F9 2095 Depart at 6:50pm from St. Louis (STL) Fly for 3h 38m Arrive at 8:28pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 2m

    Fri Nov 10th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 412
    Frontier Airlines
    6:21pm - 11:31pm
    Mon Nov 6th
    7h 10m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Nov 6th 2023 Frontier Airlines · F9 2095 Depart at 6:21pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:59pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 31m

    Mon Nov 6th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 412
    Frontier Airlines
    6:21pm - 11:31pm
    Mon Oct 9th
    7h 10m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 9th 2023 Frontier Airlines · F9 2095 Depart at 6:21pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:59pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 31m

    Mon Oct 9th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    8:45am - 1:24pm
    Thu Oct 26th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Thu Oct 26th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Thu Oct 26th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    8:45am - 1:24pm
    Mon Oct 23rd
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 23rd 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Mon Oct 23rd 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    8:45am - 1:24pm
    Mon Oct 16th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 16th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Mon Oct 16th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    8:45am - 1:24pm
    Thu Oct 19th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Thu Oct 19th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Thu Oct 19th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    8:45am - 1:24pm
    Fri Nov 3rd
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Nov 3rd 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Fri Nov 3rd 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    8:45am - 1:24pm
    Sun Nov 5th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sun Nov 5th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sun Nov 5th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    6:50pm - 11:31pm
    Fri Nov 3rd
    6h 41m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Nov 3rd 2023 Frontier Airlines · F9 2095 Depart at 6:50pm from St. Louis (STL) Fly for 3h 38m Arrive at 8:28pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 2m

    Fri Nov 3rd 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    6:50pm - 11:31pm
    Fri Oct 27th
    6h 41m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Oct 27th 2023 Frontier Airlines · F9 2095 Depart at 6:50pm from St. Louis (STL) Fly for 3h 38m Arrive at 8:28pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 2m

    Fri Oct 27th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    6:21pm - 11:31pm
    Mon Oct 30th
    7h 10m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 30th 2023 Frontier Airlines · F9 2095 Depart at 6:21pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:59pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 31m

    Mon Oct 30th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    6:21pm - 11:31pm
    Mon Oct 23rd
    7h 10m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 23rd 2023 Frontier Airlines · F9 2095 Depart at 6:21pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:59pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 31m

    Mon Oct 23rd 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 420
    Frontier Airlines
    6:21pm - 11:31pm
    Mon Oct 16th
    7h 10m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 16th 2023 Frontier Airlines · F9 2095 Depart at 6:21pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:59pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 31m

    Mon Oct 16th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 423
    Frontier Airlines
    8:45am - 1:24pm
    Thu Nov 2nd
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Thu Nov 2nd 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Thu Nov 2nd 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 428
    Frontier Airlines
    8:45am - 1:24pm
    Sat Oct 14th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Oct 14th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sat Oct 14th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 428
    Frontier Airlines
    5:17pm - 12:31am
    Mon Oct 9th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 9th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Mon Oct 9th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 435
    Frontier Airlines
    8:45am - 1:24pm
    Fri Oct 27th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Oct 27th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Fri Oct 27th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 435
    Frontier Airlines
    8:45am - 1:24pm
    Mon Oct 30th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 30th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Mon Oct 30th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 435
    Frontier Airlines
    5:17pm - 12:31am
    Mon Oct 16th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 16th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Mon Oct 16th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 443
    Frontier Airlines
    8:45am - 1:24pm
    Mon Nov 13th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Nov 13th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Mon Nov 13th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 492
    Frontier Airlines
    8:45am - 1:24pm
    Fri Oct 13th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Oct 13th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Fri Oct 13th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 501
    Frontier Airlines
    8:45am - 1:24pm
    Fri Oct 20th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Oct 20th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Fri Oct 20th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 515
    Frontier Airlines
    5:17pm - 12:31am
    Fri Oct 13th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Oct 13th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Fri Oct 13th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 531
    Frontier Airlines
    8:45am - 1:24pm
    Sat Oct 7th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sat Oct 7th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sat Oct 7th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 534
    Frontier Airlines
    6:21pm - 11:31pm
    Mon Nov 13th
    7h 10m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Nov 13th 2023 Frontier Airlines · F9 2095 Depart at 6:21pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:59pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 31m

    Mon Nov 13th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 569
    Frontier Airlines
    8:45am - 1:24pm
    Sun Oct 29th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sun Oct 29th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sun Oct 29th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 579
    Frontier Airlines
    5:17pm - 12:31am
    Fri Oct 6th
    9h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Oct 6th 2023 Frontier Airlines · F9 701 Depart at 5:17pm from St. Louis (STL) Fly for 2h 26m Arrive at 6:43pm in Denver (DEN)

    Layover in Denver for 4h 17m

    Fri Oct 6th 2023 Frontier Airlines · F9 833 Depart at 11:00pm from Denver (DEN) Fly for 2h 31m Arrive at 12:31am in Ontario (ONT)

  • USD 591
    Frontier Airlines
    8:45am - 1:24pm
    Thu Nov 9th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Thu Nov 9th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Thu Nov 9th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 599
    Frontier Airlines
    6:17pm - 11:31pm
    Sun Oct 29th
    7h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sun Oct 29th 2023 Frontier Airlines · F9 2095 Depart at 6:17pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:55pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 35m

    Sun Oct 29th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 602
    Frontier Airlines
    8:45am - 1:24pm
    Mon Oct 9th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Mon Oct 9th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Mon Oct 9th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 657
    Frontier Airlines
    8:45am - 1:24pm
    Sun Oct 22nd
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sun Oct 22nd 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sun Oct 22nd 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 667
    Frontier Airlines
    8:45am - 1:24pm
    Wed Oct 11th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Wed Oct 11th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Wed Oct 11th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 668
    Frontier Airlines
    8:45am - 1:24pm
    Thu Oct 5th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Thu Oct 5th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Thu Oct 5th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 689
    Frontier Airlines
    6:17pm - 11:31pm
    Sun Oct 15th
    7h 14m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sun Oct 15th 2023 Frontier Airlines · F9 2095 Depart at 6:17pm from St. Louis (STL) Fly for 3h 38m Arrive at 7:55pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 35m

    Sun Oct 15th 2023 Frontier Airlines · F9 2189 Depart at 10:30pm from Las Vegas (LAS) Fly for 1h 1m Arrive at 11:31pm in Ontario (ONT)

  • USD 700
    Frontier Airlines
    8:45am - 1:24pm
    Sun Nov 12th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sun Nov 12th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sun Nov 12th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 702
    Frontier AirlinesUnited Airlines
    3:09pm - 8:27pm
    Tue Oct 17th
    7h 18m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Tue Oct 17th 2023 Frontier Airlines · F9 701 Depart at 3:09pm from St. Louis (STL) Fly for 2h 28m Arrive at 4:37pm in Denver (DEN)

    Layover in Denver for 2h 30m

    Tue Oct 17th 2023 United Airlines · UA 1335 Depart at 7:07pm from Denver (DEN) Fly for 2h 20m Arrive at 8:27pm in Ontario (ONT)

  • USD 714
    Frontier Airlines
    8:45am - 1:24pm
    Sun Oct 8th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Sun Oct 8th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Sun Oct 8th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

  • USD 733
    Frontier Airlines
    8:45am - 1:24pm
    Fri Nov 10th
    6h 39m
    St. Louis (STL) → Ontario (ONT)
    1 Stop

    Fri Nov 10th 2023 Frontier Airlines · F9 699 Depart at 8:45am from St. Louis (STL) Fly for 2h 24m Arrive at 10:09am in Denver (DEN)

    Layover in Denver for 1h 51m

    Fri Nov 10th 2023 Frontier Airlines · F9 975 Depart at 12:00pm from Denver (DEN) Fly for 2h 24m Arrive at 1:24pm in Ontario (ONT)

@sarahbb1
Sarah Belizaire
@sarahbb1

Have flexible travel plans or looking for alternative routes given the chaos? Check out all the connection possibilities via a super helpful site created by @ismaelyws flightlist.io thanks to @andy_travels for the recommendation #travel #flights

@eyupitsjohn
John Ford
@eyupitsjohn

There seem to be lots of sites launching at the moment that promise to find you cheap flights but not many have the professional finish of Flightlist by @ismaelyws #travel #flights

@andy_travels
Andy Travels
@andy_travels

@ismaelyws Just tried out Flightlist for the first time. Really nice idea, well made, and just what I need at the moment 👍

@travelwitbender
Travel With Bender
@travelwitbender

Did you spot my recent article about how to score cheap one way flights? ✈️ FlightList is my new secret tool for discovering cheap routes, within a departure date range. Plus you can also search by country/region for departures & destinations. Powerful! 💪

Explore Flight Options

Cheap Flight Search Tips

Tips to help you find the cheapest flights from St. Louis to Ontario (STL to ONT).

  • Book 45-90 days before your departure date.
  • Fly during weekdays (Monday-Thursday).
  • Airfare Sales: Airlines sometimes offer huge discounts and since we take a bottom-up approach these flights will appear first in the results, so check back regularly because they don't usually last long.

Why I Built FlightList

❝As someone who works remotely & travels frequently, I always book one way flights and I'm flexible on my departure dates. I look for the best deals. Most sites require you to enter a specific departure date and clutter the page with uneccessary options, images and ads. I want something simple and minimal which allows me to search by departure date range & display a list of flights with the ability to filter according to my needs. So, I built FlightList to solve my own problem & help other travelers who may have the same frustration. It's how I imagine a flight booking site should be.❞

- Hans Desjarlais, Founder & Creator Hans Desjarlais