Sir John Sinclair-Wemyss Arbuthnot, 1st Baronet, MBE, TD (11 February 1912 – 13 June 1992) was a British Conservative Party politician.

Having been a cadet of the Junior Division of the Officer Training Corps while a pupil of Eton College, he was commissioned as a second lieutenant on 28 June 1939 in the Royal Artillery, Territorial Army.

[1] Arbuthnot served in World War II in the Royal Artillery, rising to the rank of Major.

In the 1943 King's Birthday Honours, Captain (temporary Major) Arbuthnot was appointed Member of the Order of the British Empire (MBE).

[3] Arbuthnot stood for election in Don Valley in 1935 and Dover in 1945, losing to Labour candidates both times.