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

AAAmerican Airlines

Round Trip•Economy

SEA

Seattle–Tacoma International Airport

Seattle / Tacoma, United States

STL

Lambert-Saint Louis International Airport

St. Louis, United States

$361 USD

-56%$158 USD

Verified Oct 31, 2025 at 12:51 AM

December 2025

Today

Mon

Tue

Wed

Thu

Fri

Sat

Sun

1$308 2$184 3$158 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$283 18$435 19$459 20$500 21$435 22$445 23$421 24$333 25$216 26$252 27$243 28$243 29$234 30$234 31$207 1 2 3 4

Rare Availability

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

Thursday, December 18th, 2025

10 round-trip options

Returning

Tue, Dec 23, 2025•5 Day Trip

$457 USD

Google Flights

Returning

Wed, Dec 24, 2025•6 Day Trip

$459 USD

Google Flights

Returning

Thu, Dec 25, 2025•7 Day Trip

$457 USD

Google Flights

Returning

Fri, Dec 26, 2025•8 Day Trip

$619 USD

Google Flights

Returning

Sat, Dec 27, 2025•9 Day Trip

$713 USD

Google Flights

Returning

Sun, Dec 28, 2025•10 Day Trip

$660 USD

Google Flights

Returning

Mon, Dec 29, 2025•11 Day Trip

$590 USD

Google Flights

Returning

Tue, Dec 30, 2025•12 Day Trip

$480 USD

Google Flights

Returning

Wed, Dec 31, 2025•13 Day Trip

$480 USD

Google Flights

Returning

Thu, Jan 1, 2026•14 Day Trip

$435 USD

Google Flights