Kenneth was educated at Westminster School; at Caius College, Cambridge, and at St George's Hospital. He also studied in Paris, New York, and in Boston. He took the diplomas of M.R.C.S. and L..R.C.P. in 1903. He then graduated at Cambridge as B.A. and B.C. in 1904. In 1905 he graduated M.B., and took the M.R.C.P. in 1908. He became a well known oarsman and had rowed for the London Rowing Club at Henley. After filling the posts of clinical assistant for out-patients at Paddington Green Children's Hospital, as assistant house-surgeon at St George's Hospital, and as house-physician of the Victoria Hospital for Children, Chelsea, he went into practice in London. He held the appointments of physician to the Belgrave Hospital for Children, assistant physician to the Royal Hospital for Diseases of the Chest, City Road, and medical registrar of the Prince of Wales's Hospital, Tottenham. At the outbreak of war, he served for a while as a special constable, then on 1st April 1915 he took a temporary commission as lieutenant in the R.A.M.C. After completing one year's service he was promoted to captain. Kenneth was the son of George and Julia Kellie of London; and the husband of Constance Kellie.