Southwest® flights from Ontario/LA to Portland, ME from $185

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Low fares from Ontario/LA to Portland, ME

$

Ontario/LA (ONT)to

Portland, ME (PWM)
Depart: 11/10/2026

One-way

Basic

From
$185
Seen: 14 hrs ago

Ontario/LA (ONT)to

Portland, ME (PWM)
Depart: 10/05/2026

One-way

Basic

From
$210
Seen: 12 hrs ago

Ontario/LA (ONT)to

Portland, ME (PWM)
Depart: 12/10/2026

One-way

Basic

From
$215
Seen: 14 hrs ago

Ontario/LA (ONT)to

Portland, ME (PWM)
Depart: 11/10/2026

One-way

Choice

From
$240
Seen: 14 hrs ago

Ontario/LA (ONT)to

Portland, ME (PWM)
Depart: 10/05/2026

One-way

Choice

From
$265
Seen: 12 hrs ago

Ontario/LA (ONT)to

Portland, ME (PWM)
Depart: 12/10/2026

One-way

Choice

From
$270
Seen: 14 hrs ago

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Explore flights from Ontario/LA to Portland, ME

Sep 2026
From$335*
Seen: 6 hrs ago
One Way/Basic
Oct 2026
From$210*
Seen: 12 hrs ago
One Way/Basic
Nov 2026
From$185*
Seen: 14 hrs ago
One Way/Basic
cmp-daily-histogram-bars-legend-min-price-aria-label $210
Displaying fares for September-2026
  • ONT–PWM, 09/14/2026: From $355
    14

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    18

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  • ONT–PWM, 09/20/2026: From $335
    20

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    OCT

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  • ONT–PWM, 10/03/2026: From $296
    03

    Sat

  • ONT–PWM, 10/04/2026: From $385
    04

    Sun

  • ONT–PWM, 10/05/2026: From $210
    05

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    11

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    • Range$210-$385

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

    Flight Details

    Departing from:
    LA/Ontario International Airport
    Arriving at:
    Portland International Jetport
    Distance:
    2598 miles

    Route Information

    39† Weekly flights

    † Weekly flights based on DOT published scheduled average flights Monday through Sunday between 9/1/2025 and 9/30/2025. Note: route may not operate every day of the week.

    ‡ Nonstop flights based on DOT published scheduled average flights Monday through Sunday between 9/1/2025 and 9/30/2025.

    Questions we hear the most

    There are 39 weekly flights from Ontario/LA to Portland, ME on Southwest Airlines.
    To find the lowest fares by day and time to fly Ontario/LA to Portland, ME with Southwest, check out our Low Fare Calendar.
    You can rent a car at Portland International Jetport book yours with your flight.
    Yes! Flights from Ontario/LA to Portland, ME—or from here or there to anywhere—can be changed with no change fees. Fare difference may apply.
    Check the status of your upcoming Southwest flight.
    Check out the Southwest Airlines® Help Center for answers about everything Southwest.

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