SEA to IAD from $255 in economy

UAUnited Airlines

Round Trip•Economy

SEA

Seattle–Tacoma International Airport

Seattle / Tacoma, United States

IAD

Washington Dulles International Airport

Washington, United States

$450 USD

-43%$255 USD

Verified 13 days ago

September 2026

Today

Mon

Tue

Wed

Thu

Fri

Sat

Sun

31$265 1$265 2$255 3$265 4$255 5$255 6$265 7$376 8$265 9$255 10$255 11$265 12$255 13$265 14$265 15$255 16$255 17$255 18$255 19$255 20$265 21$255 22$255 23$255 24$255 25$306 26$316 27$316 28$306 29$306 30$306 1$357 2$357 3$357 4$357

Rare Availability

9% of dates checked are available within 10% of the lowest price

Friday, September 4th, 2026

7 round-trip options

Returning

Thu, Sep 10, 2026•6 Day Trip

$294 USD

Google Flights

Returning

Fri, Sep 11, 2026•7 Day Trip

$255 USD

Google Flights

Returning

Sat, Sep 12, 2026•8 Day Trip

$255 USD

Google Flights

Returning

Mon, Sep 14, 2026•10 Day Trip

$255 USD

Google Flights

Returning

Tue, Sep 15, 2026•11 Day Trip

$265 USD

Google Flights

Returning

Wed, Sep 16, 2026•12 Day Trip

$265 USD

Google Flights

Returning

Thu, Sep 17, 2026•13 Day Trip

$265 USD

Google Flights

Seattle / Tacoma (SEA) to Washington (IAD) flight deal in economy from $255

Seattle–Tacoma International Airport

Washington Dulles International Airport

September 2026

Friday, September 4th, 2026