St Mary's Hospital, London
Colebrook was educated at the Grammar School in Guildford (1891–96), Westbourne High School in Bournemouth (1896–99) and Christ's College Blackheath in Kent (1899 - 1900). Colebrook started his medical training at the London Hospital Medical College after which he won a scholarship to St Mary's Hospital, London, graduating in 1906 with M.B. and B.S. (Lond). degrees.