San Nicolas is a fifth class municipality in the province of Batangas, Philippines. According to the 2010 census, it has a population of 20,599 people. It is the smallest municipality in Batangas with 14.37 square kilometers of land area, which includes half of the Taal Volcano island.
In 1955 the barrios of San Nicolas, Gipit, Bangin, Pansipit, Calangay, Sinturisan, Talang, Abilo, Balete, Bancora, Saimsim, Maabud, Mulawin, Tambo, Calumala, Alasas, Calawit and Pulangbato, then part of the municipality of Taal, were separated and constituted into a new and separate municipality known as San Nicolas.
In 1957, the following sitios were converted from their mother barrios and converted into independent barrios: Burol from Tambo, Tagodtod from Munlawin, Kalawit and Pulang-Bato from Alas-as, and Baluk-Balok from Gipit.