The Unconditional Spanish Party was a loyalist conservative political party in Puerto Rico during Spanish colonial times. It was founded in November 1870 as the Partido Liberal Conservador, later changing its name to Partido Incondicional Español in 1873. The party favored traditionalist assimilation into the political party system of Spain. It purchased the newspaper Boletín Mercantil to serve as the party's official organ for disseminating its conservative views. Most of its members belonged to the Puerto Rican Volunteers Corps.