Commander John Tapling Fremantle, 5th Baron Cottesloe, 5th Baron Fremantle, DL JP RN (born 22 January 1927) is a Baron in the Peerage of the United Kingdom and an Austrian nobleman. The son of John Walgrave Halford Fremantle, 4th Baron Cottesloe (1900–1994), he was educated at Summer Fields School and Eton College. He followed the family tradition set by his ancestor Admiral Thomas Fremantle and joined the Royal Navy in 1945. He commanded H.M.S. Palliser between 1959 and 1961, retiring from the Navy in 1966 with the rank of Commander. He was High Sheriff of Buckinghamshire in 1969.