St. Louis (STL) to San Juan (SJU) cheap flight deal from $225 USD in economy class

AAAmerican Airlines

Round Trip•Economy

STL

Lambert-Saint Louis International Airport

St. Louis, United States

SJU

Luis Muñoz Marín International Airport

San Juan, Puerto Rico

$372 USD

-40%$225 USD

Verified Sep 20, 2025 at 8:48 PM

October 2025

Today

Mon

Tue

Wed

Thu

Fri

Sat

Sun

29$400 30$400 1$400 2$400 3$400 4$355 5$355 6$355 7$355 8$355 9$400 10$355 11$250 12$298 13$232 14$225 15$225 16$298 17$225 18$225 19$225 20$225 21$225 22$298 23$298 24$225 25$225 26$225 27$225 28$225 29$225 30$225 31$225 1 2

Fair Availability

34% of dates checked are available within 10% of the lowest price

Sunday, October 12th, 2025

10 round-trip options

Returning

Fri, Oct 17, 2025•5 Day Trip

$298 USD

Google Flights

Returning

Sat, Oct 18, 2025•6 Day Trip

$298 USD

Google Flights

Returning

Sun, Oct 19, 2025•7 Day Trip

$473 USD

Google Flights

Returning

Mon, Oct 20, 2025•8 Day Trip

$305 USD

Google Flights

Returning

Tue, Oct 21, 2025•9 Day Trip

$298 USD

Google Flights

Returning

Wed, Oct 22, 2025•10 Day Trip

$298 USD

Google Flights

Returning

Thu, Oct 23, 2025•11 Day Trip

$298 USD

Google Flights

Returning

Fri, Oct 24, 2025•12 Day Trip

$298 USD

Google Flights

Returning

Sat, Oct 25, 2025•13 Day Trip

$298 USD

Google Flights

Returning

Sun, Oct 26, 2025•14 Day Trip

$473 USD

Google Flights