Southwest® flights from Philadelphia to Seattle/Tacoma from $156

Promo Code

Low fares from Philadelphia to Seattle/Tacoma

$

Philadelphia (PHL)to

Seattle/Tacoma (SEA)
Depart: 09/11/2026

One-way

Basic

From
$156
Seen: 1 hour ago

Philadelphia (PHL)to

Seattle/Tacoma (SEA)
Depart: 09/26/2026

One-way

Basic

From
$174
Seen: 23 hrs ago

Philadelphia (PHL)to

Seattle/Tacoma (SEA)
Depart: 09/19/2026

One-way

Basic

From
$174
Seen: 8 hrs ago

Philadelphia (PHL)to

Seattle/Tacoma (SEA)
Depart: 09/15/2026

One-way

Basic

From
$174
Seen: 14 hrs ago

Philadelphia (PHL)to

Seattle/Tacoma (SEA)
Depart: 09/30/2026

One-way

Basic

From
$174
Seen: 4 hrs ago

Philadelphia (PHL)to

Seattle/Tacoma (SEA)
Depart: 08/25/2026

One-way

Basic

From
$174
Seen: 14 hrs ago

Looking for more low-fare flights?

Check out the Low Fare Calendar to find a fare that works for you. Just choose the month you want to depart and return, and we’ll show you the best fares available.

Find low fares

Explore flights from Philadelphia to Seattle/Tacoma

Aug 2026
From$174*
Seen: 14 hrs ago
One Way/Basic
Sep 2026
From$156*
Seen: 1 hour ago
One Way/Basic
Oct 2026
From$174*
Seen: 19 hrs ago
One Way/Basic
cmp-daily-histogram-bars-legend-min-price-aria-label $174
Displaying fares for August-2026
  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    01

    Sat

    AUG

  • PHL–SEA, 08/02/2026: From $301
    02

    Sun

  • PHL–SEA, 08/03/2026: From $281
    03

    Mon

  • PHL–SEA, 08/04/2026: From $223
    04

    Tue

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

    Wed

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    06

    Thu

  • PHL–SEA, 08/07/2026: From $286
    07

    Fri

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

    Sat

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

    Sun

  • PHL–SEA, 08/10/2026: From $286
    10

    Mon

  • PHL–SEA, 08/11/2026: From $218
    11

    Tue

  • PHL–SEA, 08/12/2026: From $244
    12

    Wed

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    13

    Thu

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

    Fri

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    15

    Sat

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    16

    Sun

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    17

    Mon

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

    Tue

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    19

    Wed

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    20

    Thu

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

    Fri

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

    Sat

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

    Sun

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

    Mon

  • PHL–SEA, 08/25/2026: From $174
    25

    Tue

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    26

    Wed

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    27

    Thu

  • PHL–SEA, 08/28/2026: From $209
    28

    Fri

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    29

    Sat

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    30

    Sun

  • PHL–SEA: cmp-view-offers-disclaimer. Find Offers
    31

    Mon

    • Range$174-$301

    *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:
    Philadelphia International Airport
    Arriving at:
    Seattle/Tacoma International Airport
    Distance:
    2378 miles

    Route Information

    64† 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 64 weekly flights from Philadelphia to Seattle/Tacoma on Southwest Airlines.
    To find the lowest fares by day and time to fly Philadelphia to Seattle/Tacoma with Southwest, check out our Low Fare Calendar.
    You can rent a car at Seattle/Tacoma International Airport book yours with your flight.
    Yes! Flights from Philadelphia to Seattle/Tacoma—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.

    Explore Flights from Other Popular Origins

    Popular Flights from Philadelphia