Maurice FitzGerald Day (1816–1904) was a Church of Ireland bishop in the last quarter of the 19th century. Day was educated at Clonmel Endowed School and Trinity College, Dublin and ordained in 1840. He was the incumbent of St Matthias, Dublin from 1843 to 1868 when he became Dean of Limerick. He was Bishop of Cashel, Emly, Waterford and Lismore from 1872 until his retirement in 1899. He died on 13 December 1904.