From a long line of parish priests, Fisher was educated at Marlborough College and Exeter College, Oxford. He achieved high academic honours but was not interested in a university career. He was ordained priest in 1913, and taught at Marlborough for three years; in 1914, aged 27, he was appointed headmaster of Repton School where he served for 18 years. In 1932, having left Repton, he was made Bishop of Chester. In 1939 he accepted the post of Bishop of London, the third most senior post in the Church of England. His term of office began shortly after the start of the Second World War, and his organising skills were required to keep the diocese functioning despite the devastation of the London Blitz.