Michael I may refer to:
Pope Michael I of Alexandria, Coptic Pope of Alexandria and Patriarch of the See of St. Mark in 743–767 Michael I Rangabe, Byzantine Emperor (died in 844) Michael I Cerularius, Patriarch Michael I of Constantinople (c. 1000–1059) Michael I of Duklja, Prince and King of Duklja and (d. 1081) Mikhail of Vladimir (died in 1176) Michael I Komnenos Doukas (died in 1215) Michael I of Russia (1596–1645) Michael I of Poland (Michał Korybut Wiśniowiecki), King of Poland and Grand Duke of Lithuania (1640-1673) Michael I of Portugal (1802–1866) Michael I of Serbia (1823–1868) Mihály Cseszneky de Milvány et Csesznek, Michael I of Macedonia (1910–1975) Michael I of Romania (1921–2017) Michael I, regnal name of conclavist antipope David Bawden (1959-2022)
See also Michael (disambiguation)