Coadjutor(For the American businessman and founder of Gulf Oil, see William Larimer Mellon Sr. For the American philanthropist and physician, see William Larimer Mellon Jr.) William Henry Mellon (6 January 1877 – 2 February 1952) was a Scottish Roman Catholic clergyman who served as the Bishop of Galloway from 1943 to 1952. On the death of Bishop James William McCarthy on 24 December 1943, he automatically succeeded as Bishop of the Diocese of Galloway. He died in office on 2 February 1952, aged 75.