Smith married Alison Marjorie Bell in 1969; initially Mrs Alison Smith, she formally became Lady Smith when her husband received a knighthood in 1999.
Lord and Lady Smith own the island of Inchmarnock, situated off the west coast of the Isle of Bute in the Firth of Clyde, where he breeds Highland cattle and he also owns a vineyard and guest house in South Africa [REF].