Commander The Honourable John Montagu Granville Waldegrave, DSC RN (29 August 1905 – 18 February 1944) was a British naval commander during World War II.
He was awarded the DSC for anti-submarine work performed while commanding the Puffin.
From 1942 to 1943, he served in the Operations Division, attached to shore station HMS President.
On 6 September 1943, he was assigned to the cruiser HMS Penelope as executive officer.
On 29 June 1940, Waldegrave married Lady Hersey Boyle (11 July 1914 – 7 February 1993), the second daughter of retired navy man Patrick Boyle, 8th Earl of Glasgow.