Alaska Airlines Flights from Ontario to Seattle

Lowest fares from Ontario to Seattle

Jul 2026
From$229*
Seen: 15 hours ago
Flight Type One Way|Saver
Aug 2026
From$129*
Seen: 15 hours ago
Flight Type One Way|Saver
Sep 2026
From$129*
Seen: 15 hours ago
Flight Type One Way|Saver
cmp-daily-histogram-bars-legend-min-price-aria-label $174
cmp-daily-histogram-bars-legend-max-price-aria-label $399
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    • Range$174-$399

    *Displayed prices have been available within the past 24 hours and may not be available at the time of booking. Fares listed may be Saver fares, which is our most restrictive fare option and subject to additional restrictions. For roundtrip journeys, the price displayed—available within the past 24 hours—is the aggregate of the lowest available fare each way. Additional baggage charges and fees for optional products and services may apply. Other terms and conditions may apply.

    One-way low-fare flights Ontario to Seattle.*

    $
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    One-way low-fare flights Ontario to Seattle.*
    From
    To
    Fare Type
    Dates
    Price
    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Sep 9, 2026

    From

    $129

    Seen: 15 hours ago

    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Sep 26, 2026

    From

    $129

    Seen: 15 hours ago

    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Oct 3, 2026

    From

    $129

    Seen: 15 hours ago

    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Oct 10, 2026

    From

    $129

    Seen: 15 hours ago

    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Oct 14, 2026

    From

    $129

    Seen: 15 hours ago

    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Oct 24, 2026

    From

    $129

    Seen: 15 hours ago

    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Nov 14, 2026

    From

    $129

    Seen: 15 hours ago

    Ontario (ONT)Seattle (SEA)One-way
    |
    Saver    		Depart: Nov 18, 2026

    From

    $129

    Seen: 15 hours ago

    *Displayed prices have been available within the past 24 hours and may not be available at the time of booking. Fares listed may be Saver fares, which is our most restrictive fare option and subject to additional restrictions. For roundtrip journeys, the price displayed—available within the past 24 hours—is the aggregate of the lowest available fare each way. Additional baggage charges and fees for optional products and services may apply. Other terms and conditions may apply.

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