Algarrobo is a barrio in the municipality of Vega Baja, Puerto Rico.

In 1899, the United States Department of War conducted a census of Puerto Rico finding that the population of Algarrobo barrio was 877.

Barrios (which are, in contemporary times, roughly comparable to minor civil divisions)[15] in turn are further subdivided into smaller local populated place areas/units called sectores (sectors in English).

Clara del Sol, Brisas de Tortuguero, Urb.

Camino del Sol I & II, Sector Los Sostre, Reparto Alexandra, Camino Los Pizarro, haciendas Baudilio, Reparto Curiel, Sector La Quince, Reparto Providencia, Reparto Latania, Sector Villa Blanca, Sector Los Marrero, El Criollo, Barriada Collazo, El Verde, Urb.