Admiral Sir John Devereux Treacher, KCB (23 September 1924 – 30 April 2018) was a senior officer in the Royal Navy who served as Commander-in-Chief Fleet from 1975 to 1977.

He served onboard the Glasgow as part of Operation Neptune, (the Normandy landings) where she made up the Gunfire Bombardment Support Force C for Omaha Beach.

[1] Treacher subsequently served onboard the Thornycroft type destroyer leader HMS Keppel (D84), participating in the Arctic convoys.

[1] Treacher volunteered to join the Fleet Air Arm and reported at RAF Booker in April 1947 for basic flying training.

[1] After relinquishing command of 849 Squadron in July 1953, Treacher was appointed to the office of the Second Sea Lord and Chief of Naval Personnel.

However, after a short stint, he was appointed flag lieutenant and personal pilot to the Senior Naval Officer, British Joint Staff Mission, Vice Admiral Sir Geoffrey Barnard.

[1] After a three-year stint at Washington D.C., Treacher was appointed executive officer of the ice patrol ship HMS Protector (A146) in May 1956.

After close to two years in the FOFT staff, he was appointed Commander (Air) of the Illustrious-class aircraft carrier HMS Victorious (R38), joining the ship on 21 May 1959.

[1] In September 1962, Treacher was appointed Naval assistant to the Third Sea Lord and Controller of the Navy, Vice Admiral Sir Michael Le Fanu.

[1] Treacher was promoted to the rank of Rear admiral and appointed Flag Officer, Carriers and Amphibious Ships (FOCAS) in July 1970.