Born at Shafton, Bluefield, Jamaica, in 1885, the eldest son of Frederick Archibald Sinclair, MB Edinburgh 1882, and his wife. He came to England at the age of sixteen, and made his own way while completing his education. At the London Hospital, which he entered in 1903, he won the Anderson and dressers' prizes. After qualifying in 1908 he served as house physician, and as house surgeon to Sir Frederick Eve and Percy Furnivall. He was also receiving room officer and resident accoucheur and was elected president of the residents' mess. In the first world war he served in France, and was promoted captain, RAMC on 1 December 1918. He was very popular, and became familiarly known as Bulgie. In 1916 he took the Edinburgh Fellowship. After the war he was appointed surgical registrar at the West London Hospital, with which he thenceforward largely identified his career. He became assistant surgeon in 1919, surgeon in 1930, and senior surgeon in 1936. He was dean of the Hospital's Postgraduate School, and continued as lecturer on surgery after the School was opened to undergraduates. He was a great teacher, preferring the conversational bedside lesson to the formal lecture. He served on the Court of Examiners of the College from 1943 to 1946. Sinclair was also senior surgeon to the King George Hospital at Ilford, where he was appointed surgeon in 1933. He was at one time surgeon to the Evelina Hospital for Children, and later consulting surgeon to the Kensington Children's Hospital. He was also consulting surgeon to Chiswick, Northwood, Twickenham, and Brentford Hospitals. He was an active member of the West London Medico-Chirurgical Society and filled the offices of secretary and president; he was also secretary of the Medical Society of London. He practised at 116 Harley Street, and later lived at 14 Upper Harley Street. Here he died peacefully on 14 November 1950, aged 65, survived by his wife, their daughter, and their son, a medical student at the London Hospital. Sinclair was a friendly, robust figure. He was always unhurried and often unpunctual, willingly expending his time for patients or colleagues, regardless of appointments. He was especially interested in the surgery of the thyroid and of the upper abdomen. Publications: Stovaine spinal anaesthesia. *W Lond med J* 1932, 37, 33. A case of diffuse polyposis of the stomach. *Brit J Surg* 1933, 20, 645. Gastric neoplasms and their treatment. *Mod Treat Yearb* 1946.