American Airlines flights from Saint Louis to Ontario

Recent searches for flights from Saint Louis to Ontario

Jul 2026
From$743*
Updated: 6 hours ago
Round tripIEconomy
Aug 2026
From$367*
Updated: 6 hours ago
Round tripIEconomy
Sep 2026
From$367*
Updated: 6 hours ago
Round tripIEconomy
cmp-daily-histogram-bars-legend-min-price-aria-label $367
cmp-daily-histogram-bars-legend-max-price-aria-label $743
Displaying fares for July-2026
  • STL–ONT: cmp-view-offers-disclaimer. Find Offers
    30

    Th

    JUL

  • STL–ONT, 07/31/26 – 08/07/26: From $743
    31

    Fr

  • STL–ONT, 08/01/26 – 08/08/26: From $567
    01

    Sa

    AUG

  • STL–ONT, 08/02/26 – 08/09/26: From $743
    02

    Su

  • STL–ONT, 08/03/26 – 08/10/26: From $743
    03

    Mo

  • STL–ONT, 08/04/26 – 08/11/26: From $567
    04

    Tu

  • STL–ONT, 08/05/26 – 08/12/26: From $567
    05

    We

  • STL–ONT, 08/06/26 – 08/12/26: From $655
    06

    Th

  • STL–ONT, 08/07/26 – 08/14/26: From $675
    07

    Fr

  • STL–ONT, 08/08/26 – 08/15/26: From $567
    08

    Sa

  • STL–ONT, 08/09/26 – 08/16/26: From $675
    09

    Su

  • STL–ONT, 08/10/26 – 08/17/26: From $675
    10

    Mo

  • STL–ONT, 08/11/26 – 08/18/26: From $567
    11

    Tu

  • STL–ONT, 08/12/26 – 08/19/26: From $567
    12

    We

  • STL–ONT, 08/13/26 – 08/20/26: From $573
    13

    Th

  • STL–ONT, 08/14/26 – 08/21/26: From $523
    14

    Fr

  • STL–ONT, 08/15/26 – 08/22/26: From $467
    15

    Sa

  • STL–ONT, 08/16/26 – 08/23/26: From $577
    16

    Su

  • STL–ONT, 08/17/26 – 08/24/26: From $487
    17

    Mo

  • STL–ONT, 08/18/26 – 08/25/26: From $467
    18

    Tu

  • STL–ONT, 08/19/26 – 08/26/26: From $467
    19

    We

  • STL–ONT, 08/20/26 – 08/27/26: From $367
    20

    Th

  • STL–ONT, 08/21/26 – 08/28/26: From $439
    21

    Fr

  • STL–ONT, 08/22/26 – 08/29/26: From $367
    22

    Sa

  • STL–ONT, 08/23/26 – 08/30/26: From $517
    23

    Su

  • STL–ONT, 08/24/26 – 08/31/26: From $367
    24

    Mo

  • STL–ONT, 08/25/26 – 09/01/26: From $367
    25

    Tu

  • STL–ONT, 08/26/26 – 09/02/26: From $367
    26

    We

  • STL–ONT: cmp-view-offers-disclaimer. Find Offers
    27

    Th

  • STL–ONT: cmp-view-offers-disclaimer. Find Offers
    28

    Fr

  • STL–ONT: cmp-view-offers-disclaimer. Find Offers
    29

    Sa

    • range$367-$743

    DisclaimerFares displayed have been collected within the last 24hrs and may no longer be available at time of booking. Modifying this information may result in a different fare. To find the most updated fare, please visit aa.com. Fares listed may be Basic Economy, which class is subject to additional terms and conditions. Additional baggage fees and charges for optional products and services may apply.

    Find deals on Saint Louis to Ontario flights

    $
    keyboard_arrow_down

    Saint Louis (STL)to

    Ontario (ONT)
    10/10/26 - 10/17/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    Saint Louis (STL)to

    Ontario (ONT)
    10/15/26 - 10/22/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    Saint Louis (STL)to

    Ontario (ONT)
    10/17/26 - 10/24/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    Saint Louis (STL)to

    Ontario (ONT)
    10/20/26 - 10/27/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    Saint Louis (STL)to

    Ontario (ONT)
    10/24/26 - 10/31/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    Saint Louis (STL)to

    Ontario (ONT)
    09/03/26 - 09/10/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    Saint Louis (STL)to

    Ontario (ONT)
    09/08/26 - 09/15/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    Saint Louis (STL)to

    Ontario (ONT)
    09/23/26 - 09/30/26

    Round trip

    Economy

    from
    $367Fare subject to changes
    Updated: 6 hours ago

    *Fares displayed have been collected within the last 24hrs and may no longer be available at time of booking. Some fares listed may include one or more connections that are Basic Economy, which class is subject to additional terms and conditions. Modifying this information may result in a different fare. To find the most updated fare, please visit aa.com. Additional baggage fees and charges for optional products and services may apply.

    Finding cheap flights from Saint Louis to Ontario

    Looking for lower fares on your trip from Saint Louis to Ontario? Here are a few ways to save.

    • Book early: Booking 1 to 3 months ahead can help you find lower fares
    • Be flexible with dates: Midweek travel, like Tuesdays and Wednesdays, can be more affordable
    • Travel during less busy periods: Flying outside peak travel times can help find lower fares and avoid crowds

    Earn up to $500 back on your next American Airlines flight plus, 30,000 bonus miles. Offers vary elsewhere. Opens another site in a new window that may not meet accessibility guidelines.

    Upgrade your flight with Main Cabin Extra

    Make your trip more comfortable with Main Cabin Extra. Enjoy benefits like:

    • Extra legroom: More space with seats at the front of the Main Cabin or in exit rows.
    • Early boarding: Preferred Group 5 boarding allows easier access to overhead bins.
    • Complimentary drinks: Enjoy beer, wine and spirits on flights with full beverage service.

    Discover how Main Cabin Extra can enhance your trip.

    American Airlines flights from Saint Louis to Ontario