San Carlos Institute, Cuban heritage center in Key West, United States.

San Carlos Institute is a museum and cultural building in Key West with Cuban-influenced architectural design that houses a library, art gallery, theater, and educational spaces. The facility on Duval Street offers various exhibition rooms and performance venues for visitors.

Founded on 11 November 1871 by Cuban exiles Juan María Reyes and José Dolores Poyo, the San Carlos opened on Anne Street during the Ten Years' War. It moved to Fleming Street in 1884, was damaged in the 1886 fire, and was rebuilt at 516 Duval Street in 1890 under Martín Herrera. It closed in 1973 and reopened in January 1992 after a $2.8 million state-funded restoration.

The institute's name honors San Carlos, the patron saint of Cuba, and its 375-seat theater hosts the Key West Literary Seminar each January, with readings, workshops and panels. The San Carlos also sponsors the Key West Film Festival and the Key West Songwriter's Festival, serving as a venue for screenings, receptions and musical performances.

The institute stands at 516 Duval Street, and its 375-seat theater hosts many of the main events of the Key West Literary Seminar each January. The building also serves as a venue for receptions and screenings during the Key West Film Festival and for performances at the Key West Songwriter's Festival. The permanent exhibits, including the Martí installation and the Pichs Collection on Cuban postal history, can be viewed inside.

The building's facade partially collapsed in 1981, injuring a passing tourist and prompting a demolition threat. Florida provided $2.8 million in grants for restoration, and Miami attorney Rafael A. Peñalver Jr. helped raise support. The institute reopened in January 1992 with a three-day celebration.