The son of Vice-Admiral Charles Andrew Fountaine and his wife, Louisa (Maclean), Andrew Fountaine succeeded his father as Lord of the Manors of Narford, Southacre, and Newton in 1946. He was educated at Stowe, Magdalene College, Cambridge, and Army College, Aldershot. He served as County Councillor in 1951, and was formerly Deputy Chief Inspector Naval Ordnance. Fellow of the Chemical Society in 1938, from 1939-45 he served in World War II in the Royal Navy, was wounded at Okinawa in 1945 and invalided in 1947. Fountaine married Anne Fairfax, only daughter of Lt.-Col. Arthur Fairfax Senior, Officer of the Order of the British Empire, on 26 March 1949. They had two children, Charles Andrew (Jr.) and Caroline Anne, and were divorced in 1960. Fountaine remarried in September 1960 to Rosemary Mitcham; they had a son, Richard John, born 8 March 1961.