William Turner was born at Kilmallock, Ireland.  He received his education at Mungret College in Limerick, at the Royal University of Ireland, and at the Propaganda College in Rome.  He was ordained to the priesthood on August 13, 1893. The following year he began his career as a professor at St. Paul's Seminary.  He later became professor of philosophy at the Catholic University of America. 

On March 10, 1919, Turner was appointed the sixth Bishop of Buffalo, New York by Pope Benedict XV.  He received his episcopal consecration on the following March 30 from Cardinal James Gibbons, with Bishops Denis J. O'Connell and Michael Joseph Curley serving as co-consecrators. 

Bishop Turner began Catholic Charities in 1924, and established more than 30 new parishes during his administration.  He died at age 65.