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

UAUnited Airlines

Round Trip•Economy

SJU

Luis Muñoz Marín International Airport

San Juan, Puerto Rico

STL

Lambert-Saint Louis International Airport

St. Louis, United States

$522 USD

-57%$225 USD

Verified Dec 1, 2025 at 5:23 AM

December 2025

Today

Mon

Tue

Wed

Thu

Fri

Sat

Sun

1$713 2$627 3$568 4$602 5$596 6$596 7$634 8$594 9$556 10$556 11$593 12$569 13$690 14$728 15$692 16$655 17$485 18$472 19$472 20$472 21$429 22$378 23$327 24$316 25$293 26$375 27$535 28$547 29$437 30$498 31$430 1$569 2$823 3$958 4$812

Rare Availability

5% of dates checked are available within 10% of the lowest price

Tuesday, December 23rd, 2025

10 round-trip options

Returning

Sun, Dec 28, 2025•5 Day Trip

$649 USD

Google Flights

Returning

Mon, Dec 29, 2025•6 Day Trip

$604 USD

Google Flights

Returning

Tue, Dec 30, 2025•7 Day Trip

$559 USD

Google Flights

Returning

Wed, Dec 31, 2025•8 Day Trip

$401 USD

Google Flights

Returning

Thu, Jan 1, 2026•9 Day Trip

$376 USD

Google Flights

Returning

Fri, Jan 2, 2026•10 Day Trip

$482 USD

Google Flights

Returning

Sat, Jan 3, 2026•11 Day Trip

$396 USD

Google Flights

Returning

Sun, Jan 4, 2026•12 Day Trip

$372 USD

Google Flights

Returning

Mon, Jan 5, 2026•13 Day Trip

$372 USD

Google Flights

Returning

Tue, Jan 6, 2026•14 Day Trip

$327 USD

Google Flights