Ernesto Ruffini (19 January 1888—11 June 1967) was an Italian Catholic prelate who served as Archbishop of Palermo from 1945 to 1967 and was made a Cardinal by Pope Pius XII. Ruffini became a prominent figure in the Roman Curia as Secretary of the Congregatio de Institutione Catholica from 1928 to 1945, dealing with Catholic education. Ruffini was particularly interested in science, having founded the Unione Medico-Biologica San Luca and was Perfect of Studies at the Pontifical Lateran University.
During the Second World War, Ruffini controversially allowed Jews to stay at the Palace of San Callisto in Trastevere where he was staying, instead of stepping aside to have them be deported for resettlement in the East. He was opposed to communism and as Archbishop of Palermo was noted for voicing sympathy in favour of Francisco Franco, leader of Spain. He resisted the modernists at the Second Vatican Council as a member of the Coetus Internationalis Patrum. Ruffini opposed Nostra Aetate particularly for its liberal position on Judaism (which Ruffini regarded as a fundamentally anti-Christian religious system), Gaudium et Spes, Sacrosanctum Concilium, and Dignitatis Humanae.