António Mendes Belo was a Portuguese prelate of the Catholic Church, who served as Patriarch of Lisbon from 1907 until his death. He was made a Cardinal of the Roman Catholic Church in 1911, though his elevation to that rank was not announced until 1914. He was Auxiliary Bishop of Lisbon from 1884 to 1888 and Archbishop of Faro from 1888 to 1906.

The Patriarch of Lisbon, also called the Cardinal-Patriarch of Lisbon once he has been made cardinal, is the ordinary bishop of the Archdiocese of Lisbon. He is one of the few patriarchs in the Latin Church of the Catholic Church, along with the Patriarchs of Venice, the East Indies, and Jerusalem.