Brian Patrick Ashby CBE (10 November 1923 – 5 June 1988) was the fifth Roman Catholic Bishop of Christchurch, New Zealand. He was appointed by Pope Paul VI on 11 July 1964, resigned the see on 4 July 1985, and died on 5 June 1988. He was the leading New Zealand Catholic bishop in attempting to implement the decrees of the Vatican Council II and he was the leading bishop on social justice issues.