The Catholic Encyclopedia

The Catholic Encyclopedia: An International Work of Reference on the Constitution, Doctrine, Discipline, and History of the Catholic Church, also referred to as the Old Catholic Encyclopedia and the Original Catholic Encyclopedia, is an English-language encyclopedia about Catholicism published in the United States. It was designed "to give its readers full and authoritative information on the entire cycle of Catholic interests, action and doctrine".

The first volume of the Catholic Encyclopedia appeared in March 1907 and the last three volumes appeared in 1912, followed by a master index volume in 1914 and later supplementary volumes. Its successor, the New Catholic Encyclopedia, was first published by the Catholic University of America in 1967.