John Anthony Lynn was born on 27 July 1941 in Caversham, Berkshire. His father was a pharmacist. Educated at the Thomas Hardye School in Dorchester, he studied medicine at London University and trained at King’s College Hospital Medical School, graduating MB, BS in 1964. After various house jobs, he spent a year in general practice and, in 1967, travelled to Ascension Island in the South Atlantic where he was employed as a physician and surgeon by the Cable and Wireless Company. In this role he was able to obtain a great deal of useful experience. Following a spell at Chester Royal Infirmary working with Sir John Wakeley, he passed the fellowship of the college in I971. He then took up a surgical research fellowship at the Boston University Medical Centre in the USA and spent more or less two years gaining the experience of endocrine surgery that he was able to put to good use when he wrote up his thesis for his 1977 MS. After Boston he worked as a surgical registrar in Dorset and subsequently at the Westminster Hospital, working under Gerald Westbury. He was an Arris and Gale lecturer at the college in 1977 and the same year was appointed lecturer in Professor Harold Ellis' surgical department at Westminster Hospital Medical School, London. In 1978 he was appointed to the Hammersmith Hospital and the Royal Postgraduate Medical School as consultant endocrine surgeon. In the nearly 30 years he spent in that post he established an international reputation in his field and built up the UK’s biggest and most prestigious endocrine surgery unit. He was also honorary senior lecturer in the department of surgery at Imperial College of Science, Medicine and Technology. After retiring at age 65 in 2006, he maintained his private practice almost up until his death. He was a founder member of the British Endocrine Surgical Group which was later to become the British Association of Endocrine & Thyroid Surgeons. He lectured worldwide and published extensively on all aspects of endocrine surgery. While at the Westminster he met his wife Ann née Drury who was working there as a senior house officer. She became a fellow of the Royal College of Radiologists and a consultant oncologist with a special interest in thyroid cancer, breast cancer and sarcomas. He died from metastatic renal carcinoma on 16 September 2019 aged 78, survived by Ann and their son, William, also a surgeon.