St. John's University (St. John'sSt. John's University is the largest Catholic university in the United States, formerly known as the College founded by the Vicentian Society in 1870 in Queens County, New York, and the St. John's Union founded by the Congregation of the Mission in 1872. There are six campuses: Queens, New York (the main campus); Staten Island; Manhattan; Oakdale; Rome (in Italy); and Paris (in France).