American Airlines flights from Ontario to Seattle

Recent searches for flights from Ontario to Seattle

Aug 2026
From$432*
Updated: 8 hours ago
Round tripIEconomy
Sep 2026
From$267*
Updated: 8 hours ago
Round tripIEconomy
Oct 2026
From$267*
Updated: 8 hours ago
Round tripIEconomy
cmp-daily-histogram-bars-legend-min-price-aria-label $322
cmp-daily-histogram-bars-legend-max-price-aria-label $786
Displaying fares for August-2026
  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    12

    We

    AUG

  • ONT–SEA, 08/13/26 – 08/20/26: From $613
    13

    Th

  • ONT–SEA, 08/14/26 – 08/21/26: From $720
    14

    Fr

  • ONT–SEA, 08/15/26 – 08/22/26: From $628
    15

    Sa

  • ONT–SEA, 08/16/26 – 08/23/26: From $720
    16

    Su

  • ONT–SEA, 08/17/26 – 08/21/26: From $613
    17

    Mo

  • ONT–SEA, 08/18/26 – 08/25/26: From $521
    18

    Tu

  • ONT–SEA, 08/19/26 – 08/26/26: From $573
    19

    We

  • ONT–SEA, 08/20/26 – 08/27/26: From $786
    20

    Th

  • ONT–SEA, 08/21/26 – 08/28/26: From $622
    21

    Fr

  • ONT–SEA, 08/22/26 – 08/29/26: From $573
    22

    Sa

  • ONT–SEA, 08/23/26 – 08/30/26: From $590
    23

    Su

  • ONT–SEA, 08/24/26 – 08/31/26: From $590
    24

    Mo

  • ONT–SEA, 08/25/26 – 09/01/26: From $504
    25

    Tu

  • ONT–SEA, 08/26/26 – 09/02/26: From $432
    26

    We

  • ONT–SEA, 08/27/26 – 09/03/26: From $567
    27

    Th

  • ONT–SEA, 08/28/26 – 09/04/26: From $622
    28

    Fr

  • ONT–SEA, 08/29/26 – 09/05/26: From $432
    29

    Sa

  • ONT–SEA, 08/30/26 – 09/06/26: From $472
    30

    Su

  • ONT–SEA, 08/31/26 – 09/02/26: From $492
    31

    Mo

  • ONT–SEA, 09/01/26 – 09/08/26: From $472
    01

    Tu

    SEP

  • ONT–SEA, 09/02/26 – 09/09/26: From $398
    02

    We

  • ONT–SEA, 09/03/26 – 09/10/26: From $567
    03

    Th

  • ONT–SEA, 09/04/26 – 09/11/26: From $627
    04

    Fr

  • ONT–SEA, 09/05/26 – 09/12/26: From $413
    05

    Sa

  • ONT–SEA, 09/06/26 – 09/13/26: From $398
    06

    Su

  • ONT–SEA, 09/07/26 – 09/14/26: From $493
    07

    Mo

  • ONT–SEA, 09/08/26 – 09/15/26: From $322
    08

    Tu

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    09

    We

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    10

    Th

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    11

    Fr

    • range$322-$786

    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 Ontario to Seattle flights

    $
    keyboard_arrow_down

    Ontario (ONT)to

    Seattle (SEA)
    09/15/26 - 09/22/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 hours ago

    Ontario (ONT)to

    Seattle (SEA)
    09/19/26 - 09/26/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 hours ago

    Ontario (ONT)to

    Seattle (SEA)
    09/23/26 - 09/30/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 hours ago

    Ontario (ONT)to

    Seattle (SEA)
    10/14/26 - 10/21/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 hours ago

    Ontario (ONT)to

    Seattle (SEA)
    10/24/26 - 10/31/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 hours ago

    Ontario (ONT)to

    Seattle (SEA)
    10/28/26 - 11/04/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 hours ago

    Ontario (ONT)to

    Seattle (SEA)
    10/31/26 - 11/07/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 hours ago

    Ontario (ONT)to

    Seattle (SEA)
    10/06/26 - 10/13/26

    Round trip

    Economy

    from
    $267Fare subject to changes
    Updated: 8 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 Ontario to Seattle

    Looking for lower fares on your trip from Ontario to Seattle? 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 Ontario to Seattle