Major General Sir (Thomas) John Willoughby Winterton KCB, KCMG, CBE, DL (13 April 1898 – 14 December 1987) was a British Army officer who was the Military Governor and Commander of the British and US Zone of the Free Territory of Trieste from 1951 to 1954.

[3][1] After the war, he married, in 1921, and was adjutant to a Territorial Army (TA) unit, from 1925 to 1929, before being posted to Burma in 1930 and later attended the Staff College, Quetta from 1936 to 1937.

[4] He served in World War II initially as Deputy Adjutant and Quartermaster General for I Corps in which role he took part in the Dunkirk evacuation.

[3] He went on to be Military Governor and Commander of the British and US Zone of the Free Territory of Trieste from 1951 to 1954 before retiring in 1955.

He then converted to Catholicism, joined the Oratory of Saint Philip Neri in 1961 (taking the religious name "Gregory"), and was ordained as a Catholic priest in 1963.