John Leonard Dawson CVO FRCS (30 September 1932 – 16 May 1999) was an English surgeon particularly known for his work in the field of liver disease.

[1][2][3] He was president of the surgical section of the Royal Society of Medicine,[1][3] served as vice-chair of the British Journal of Surgery (1981–89), and also worked for the Medical Appeals Tribunal Service.

[2] Described as an "excellent diagnostician"[1] who offered "sympathetic and meticulous" care after surgery,[1][3] one of his peers called Dawson "the best general surgeon in London in the 1970s and 1980s".

He pioneered several surgical techniques, including radical tumour resection, injection sclerotherapy and portosystemic shunt surgery for portal hypertension.

[1][3] His hepatic focus was important in developing the Liver Unit at King's College Hospital, which was established in 1966 by Roger Williams[4] and soon built an international reputation.