With a land area of 5.41 square miles (14.0 km2), Caimito is the second largest barrio in the municipality of San Juan, Puerto Rico.

Located in the southern part of San Juan, Caimito is bordered by barrios Tortugo and Quebrada Arenas to the west, by Monacillo to the north, by Cupey to the east and by the municipality of Caguas to the south.

[6] Assigned as a suburb of Río Piedras in 1835 by Pedro Tomás de Córdova, who was Captain General of Puerto Rico from 1816 to 1836, Caimito consisted of 3,595.30 acres or land or roughly 5.16 square miles.

Historian Dr. Fernando Picó S.J., wrote a book about the history and genealogy of the area, published in 1989, called Vivir en Caimito.

[9] The neighborhood commissioner (comisario de barrio was the main representative of Caimito to the Mayor of Río Piedras.