Southwest® flights from Seattle/Tacoma to Washington, D.C. (Dulles) from $129

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Low fares from Seattle/Tacoma to Washington, D.C. (Dulles)

$

Seattle/Tacoma (SEA)to

Washington, D.C. (Dulles) (IAD)
Depart: 03/25/2026

One-way

Basic

From
$129
Seen: 4 hrs ago

Seattle/Tacoma (SEA)to

Washington, D.C. (Dulles) (IAD)
Depart: 03/25/2026

One-way

Choice

From
$169
Seen: 4 hrs ago

Seattle/Tacoma (SEA)to

Washington, D.C. (Dulles) (IAD)
Depart: 04/09/2026

One-way

Basic

From
$204
Seen: 13 hrs ago

Seattle/Tacoma (SEA)to

Washington, D.C. (Dulles) (IAD)
Depart: 04/24/2026

One-way

Basic

From
$204
Seen: 6 hrs ago

Seattle/Tacoma (SEA)to

Washington, D.C. (Dulles) (IAD)
Depart: 04/23/2026

One-way

Basic

From
$204
Seen: 3 hrs ago

Seattle/Tacoma (SEA)to

Washington, D.C. (Dulles) (IAD)
Depart: 04/13/2026

One-way

Basic

From
$224
Seen: 8 hrs ago

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Explore flights from Seattle/Tacoma to Washington, D.C. (Dulles)

*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:
Seattle/Tacoma International Airport
Arriving at:
Dulles International Airport
Distance:
2306 miles

Route Information

36† 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 36 weekly flights from Seattle/Tacoma to Washington, D.C. (Dulles) on Southwest Airlines.
To find the lowest fares by day and time to fly Seattle/Tacoma to Washington, D.C. (Dulles) with Southwest, check out our Low Fare Calendar.
You can rent a car at Dulles International Airport book yours with your flight.
Yes! Flights from Seattle/Tacoma to Washington, D.C. (Dulles)—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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