Boca () is a rural barrio in the municipality of Guayanilla, Puerto Rico. Its population in 2010 was 1,089.
Boca has of land area and of water area. In 2010, its population was 1089 with a population density of .
Boca was in Spain's gazetteers until Puerto Rico was ceded by Spain in the aftermath of the SpanishâÂÂAmerican War under the terms of the Treaty of Paris of 1898 and became an unincorporated territory of the United States. In 1899, the United States Department of War conducted a census of Puerto Rico finding that the combined population of Indios barrio and Boca barrio was 782.