He served a curacy in Dewsbury, West Yorkshire, after which he was invited to become chaplain and tutor at St Edmund Hall, Oxford, in 1931 (a post he held until 1935). Farrer was a Fellow and Chaplain of Trinity College, Oxford, from 1935 to 1960. In 1937, he married Katharine Dorothy Newton, (daughter of the Rev. Frederick Henry Joseph Newton), who would become a mystery novelist. They had one child together in 1939, a daughter Caroline, who became an ecclesiastical embroiderer.