Sir Leonard Erskine Hill FRS[1] (2 June 1866, in Bruce Castle, Tottenham – 30 March 1952, in Corton, Suffolk) was a British physiologist.

His father was George Birkbeck Hill, the famous scholar and commentator on the works of Samuel Johnson, who at the time of his birth was headmaster of Bruce Castle School.

[2][4] Hill was the second recipient of the T. K. Sidey Medal, set up by the Royal Society of New Zealand as an award for outstanding scientific research.

[5][6][7] Hill was an advocate of light therapy and in 1924 authored Sunshine and Open Air: Their Influence on Health.

[8] Hill performed research into decompression sickness, oxygen toxicity, and effects of carbon dioxide in diving.