IAD to SEA from $255 in economy

UAUnited Airlines

Round Trip•Economy

IAD

Washington Dulles International Airport

Washington, United States

SEA

Seattle–Tacoma International Airport

Seattle / Tacoma, United States

$449 USD

-43%$255 USD

Verified 14 days ago

July 2026

Today

Mon

Tue

Wed

Thu

Fri

Sat

Sun

29 30 1 2 3 4 5$972 6$734 7$674 8$703 9$725 10$734 11$698 12$653 13$586 14$629 15$587 16$689 17$587 18$536 19$512 20$494 21$499 22$504 23$564 24$520 25$510 26$460 27$399 28$438 29$434 30$431 31$465 1$431 2$388

Limited Availability

11% of dates checked are available within 10% of the lowest price

Tuesday, July 7th, 2026

8 round-trip options

Returning

Sun, Jul 12, 2026•5 Day Trip

$783 USD

Google Flights

Returning

Mon, Jul 13, 2026•6 Day Trip

$674 USD

Google Flights

Returning

Tue, Jul 14, 2026•7 Day Trip

$717 USD

Google Flights

Returning

Thu, Jul 16, 2026•9 Day Trip

$863 USD

Google Flights

Returning

Fri, Jul 17, 2026•10 Day Trip

$858 USD

Google Flights

Returning

Sat, Jul 18, 2026•11 Day Trip

$843 USD

Google Flights

Returning

Sun, Jul 19, 2026•12 Day Trip

$898 USD

Google Flights

Returning

Tue, Jul 21, 2026•14 Day Trip

$703 USD

Google Flights

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

Washington Dulles International Airport

Seattle–Tacoma International Airport

July 2026

Tuesday, July 7th, 2026