MRCS Eng LRCP Lond 1902; FACS 1920; FRCS Canada 1931.
Hubbard received his medical education at Charing Cross Hospital, London. After qualifying, Hubbard held junior positions at Charing Cross Hospital and Evenlina Hospital for Children before being appointed resident medical officer at Portland Town Free Dispensary. By 1907 Hubbard was working in general practice in Manchester, but he later went to Canada where he was surgeon at Jeffrey Hale's Hospital in Quebec.