| Sir Peter Cazalet | |
| Birth Date: | 29 July 1899 |
| Death Date: | 17 February 1982 (aged 82) |
| Allegiance: |  United Kingdom |
| Serviceyears: | 1917–1957 |
| Rank: | Vice Admiral |
| Branch: | Royal Navy |
| Commands: | HMS Durban 23rd Destroyer Flotilla HMS London Royal Naval Barracks Chatham Reserve Fleet |
| Battles: | World War I World War II |
| Awards: | Knight Commander of the Order of the British Empire Companion of the Order of the Bath Distinguished Service Order Distinguished Service Cross |
Vice-Admiral Sir Peter Grenville Lyon Cazalet KBE CB DSO DSC (29 July 1899 – 17 February 1982) was a senior Royal Navy officer who commanded the Reserve Fleet.
Cazalet joined the Royal Navy in 1917 and served as a midshipman in the battlecruiser HMS Princess Royal during World War I.[1] He also served in World War II as Commanding Officer of the cruiser HMS Durban in the Eastern Fleet from 1941 and saw action during the fall of Singapore.[2] He continued his war service as Commander of the 23rd Destroyer Flotilla from 1944.[1]
He became deputy director of Plans at the Admiralty in 1946, Commanding Officer of the cruiser HMS London in 1949 and Commodore at the Royal Naval Barracks Chatham in 1949.[1] He went on to be Chief of Staff to the Flag Officer, Central Europe in 1950, Allied Chief of Staff to the Commander-in-Chief, Mediterranean Fleet in 1953 and Flag Officer commanding the Reserve Fleet in 1955 before retiring in 1957.[1]
In retirement he was Chairman of Navy League from 1960 to 1967.[1]