Born in Canada on 23 July 1871, son of William Cox Lelean, he was educated at Hart House and St Mary's Hospital, London. During the South African War he was commissioned in the Army Medical Service and gained the Queen's medal with four clasps. In 1903 he served on the Anglo-French Boundary Commission which traced the boundaries between French and British territories from the Niger to Lake Chad. Subsequently he served in India until 1912. During the war of 1914-18 he was four times mentioned in dispatches. Retiring from the RAMC as Colonel in 1922, he was appointed to the Chair of Public Health in Edinburgh University in 1926 ultimately retiring in 1944. He was a dedicated and progressive teacher and did much to increase the co-operation of the University with the public health authorities of the city. In 1902 he married Mary Ellen, daughter of John Gillam of Penbryn, Stourbridge, who predeceased him and by whom he had two daughters. He died in London on 6 November 1956 aged 85.