Flights from Ontario/LA, CA to Seattle, WA

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Best Deals on Flights From Ontario/LA, CA (ONT) to Seattle, WA (SEA)

Nov 2026
from$144*
Last seen: 5 hours ago
One-way/Economy
Dec 2026
from$76*
Last seen: 9 hours ago
One-way/Economy
Jan 2027
from$92*
Last seen: 23 hours ago
One-way/Economy
cmp-daily-histogram-bars-legend-min-price-aria-label $76
cmp-daily-histogram-bars-legend-max-price-aria-label $364
Displaying fares for November-2026
  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    13

    Fri

    NOV

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    14

    Sat

  • ONT–SEA, Nov 15, 2026: from $227
    15

    Sun

  • ONT–SEA, Nov 16, 2026: from $192
    16

    Mon

  • ONT–SEA, Nov 17, 2026: from $194
    17

    Tue

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    18

    Wed

  • ONT–SEA, Nov 19, 2026: from $190
    19

    Thu

  • ONT–SEA, Nov 20, 2026: from $184
    20

    Fri

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    21

    Sat

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    22

    Sun

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    23

    Mon

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    24

    Tue

  • ONT–SEA, Nov 25, 2026: from $144
    25

    Wed

  • ONT–SEA, Nov 26, 2026: from $164
    26

    Thu

  • ONT–SEA, Nov 27, 2026: from $174
    27

    Fri

  • ONT–SEA, Nov 28, 2026: from $342
    28

    Sat

  • ONT–SEA, Nov 29, 2026: from $364
    29

    Sun

  • ONT–SEA, Nov 30, 2026: from $233
    30

    Mon

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    01

    Tue

    DEC

  • ONT–SEA, Dec 2, 2026: from $76
    02

    Wed

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    03

    Thu

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    04

    Fri

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    05

    Sat

  • ONT–SEA, Dec 6, 2026: from $144
    06

    Sun

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    07

    Mon

  • ONT–SEA: cmp-view-offers-disclaimer. Find Offers
    08

    Tue

  • ONT–SEA, Dec 9, 2026: from $107
    09

    Wed

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

    Thu

  • ONT–SEA, Dec 11, 2026: from $144
    11

    Fri

  • ONT–SEA, Dec 12, 2026: from $110
    12

    Sat

    • Range$76-$364

    *Prices found by others in the previous 48 hours for round-trip flights. Prices shown may also require membership in our travel club, Discount Den.

    Flights Deals from Ontario/LA, CA to Seattle, WA on Frontier

    $
    *Prices found by others in the previous 48 hours for one-way flights. Prices shown may also require membership in our travel club, Discount Den®.

    Ontario/LA, CA Seattle, WA

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