Mason came up to Trinity College, Cambridge in 1868. He was Fellow there from 1873-1884 before a brief period of employment at Wellington College as a master. In 1895 he was appointed Lady Margaret's Professor of Divinity at Cambridge, with a Fellowship at Jesus College. Both of these roles he vacanted upon being elected Master of Pembroke in 1903. During his tenure as Master he was Vice-Chancellor of the University for 1908-1910. After his resignation as Master he became a Canon of Canterbury. He was also Chaplain to the King in 1911.