Sir Anthony Arthur Duncan Montague Browne KCMG CBE DFC (8 May 1923 – 1 April 2013) was a British diplomat who was private secretary to Sir Winston Churchill during the last ten years of the latter's life. Montague Browne was the biological father of Justin Welby, Archbishop of Canterbury, but Welby learned that only after paternity testing had been taken after Montague Browne's death.