Coamo, town, south-central Puerto Rico. It lies in the southern foothills of the Cordillera Central, on the Coamo River southwest of San Juan. It was founded as a religious community in 1579, made a town in 1616, and given the title villa by Spanish royal decree in 1778. During the Spanish-American War (1898), it was the scene of a decisive battle. The town is an agricultural trading centre and manufactures coffee machinery, aircraft radio components, and sweaters. It has an 18th-century parish church, and sulfur springs are located nearby. The surrounding region is chiefly agricultural, with sugar and tobacco as its main products. Pop. (2000) 12,356; (2010) 11,522.