Wilfrid Le Gros Clark was born in Hemel Hempstead on 5 June 1895. He attended Blundell's School in Tiverton, and in 1912 entered the medical school of St. Thomas's Hospital. He qualified as a surgeon in 1916 and then joined the Royal Army Medical Corps (R.A.M.C.), with which he served in France from the beginning of 1918. He was demobilized in 1919. He then passed the Fellowship of the Royal College of Surgeons (F.R.C.S.) exam.

In 1920 Clark was appointed Principal Medical Officer in Sarawak, Borneo, a position he was to hold for three years. In addition to his medical duties he developed a deep-seated interest in natural history, especially anthropology and zoology.

In 1924 Clark was appointed Chair of Anatomy at St. Bartholomew's Hospital Medical College, first as university reader and then from 1927 as professor. In 1930 he was appointed Chair of Anatomy at St. Thomas's Hospital Medical School. In 1934 he moved to the Chair of Anatomy at Oxford University, a position he occupied until his retirement in 1962. He maintained his connection with the Oxford department in an honorary capacity until his death on 28 June 1971.

Clark was elected Fellow of the Royal Society in 1935, and knighted in 1955. In 1950 he was president of the International Anatomical Congress, 1952-1953 of the Anatomical Society, and in 1961 of the British Association for the Advancement of Science.