St. Louis (STL) to Seattle / Tacoma (SEA) flight deal from $158 USD in economy class

AAAmerican Airlines

Round Trip•Economy

STL

Lambert-Saint Louis International Airport

St. Louis, United States

SEA

Seattle–Tacoma International Airport

Seattle / Tacoma, United States

$379 USD

-58%$158 USD

Verified Nov 3, 2025 at 5:35 AM

December 2025

Today

Mon

Tue

Wed

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Sun

1$352 2$308 3$184 4$167 5$167 6$158 7$167 8$167 9$158 10$158 11$167 12$243 13$234 14$243 15$283 16$234 17$256 18$312 19$373 20$432 21$357 22$312 23$344 24$304 25$324 26$442 27$466 28$523 29$442 30$412 31$331 1 2 3 4

Rare Availability

7% of dates checked are available within 10% of the lowest price

Monday, December 22nd, 2025

10 round-trip options

Returning

Sat, Dec 27, 2025•5 Day Trip

$348 USD

Google Flights

Returning

Sun, Dec 28, 2025•6 Day Trip

$348 USD

Google Flights

Returning

Mon, Dec 29, 2025•7 Day Trip

$339 USD

Google Flights

Returning

Tue, Dec 30, 2025•8 Day Trip

$339 USD

Google Flights

Returning

Wed, Dec 31, 2025•9 Day Trip

$312 USD

Google Flights

Returning

Thu, Jan 1, 2026•10 Day Trip

$369 USD

Google Flights

Returning

Fri, Jan 2, 2026•11 Day Trip

$339 USD

Google Flights

Returning

Sat, Jan 3, 2026•12 Day Trip

$348 USD

Google Flights

Returning

Sun, Jan 4, 2026•13 Day Trip

$348 USD

Google Flights

Returning

Mon, Jan 5, 2026•14 Day Trip

$339 USD

Google Flights