Sir Oliver Grantham Forster (2 September 1925 – 3 November 1999) was a British diplomat.
He was educated at Hurstpierpoint College and King's College, Cambridge.
He joined the Foreign and Commonwealth Office in 1951 and later served as UK Ambassador to Pakistan from 1979 to 1984. He was made a Lieutenant of the Royal Victorian Order in 1961, Companion of the Order of St Michael and St George in 1976 and Knight Commander of that same order in 1983.