Papa Pius IV (31 Machi 1499 – 9 Desemba 1565) alikuwa Papa kuanzia tarehe 26 Desemba 1559/6 Januari 1560 hadi kifo chake. Alitokea Milano, Italia. Jina lake la kuzaliwa lilikuwa Giovan Angelo Medici. Alimfuata Papa Paulo IV akafuatwa na Papa Pius V. Orodha ya Mapapa https://www.vatican.va/content/vatican/en/holy-father.index.html#holy-father https://www.vatican.va/content/vatican/en/holy-father.index.html#holy-father Rendina, Claudio (1984). I papi. Storia e segreti. Rome: Newton Compton.  Freedberg, Sydney J. (1993). in Pelican History of Art: Painting in Italy, 1500–1600. Penguin Books Ltd, 429.  Papa Pius IV katika Kamusi Elezo ya Kikatoliki