Michael is the Archangel mentioned in the Book of Revelation . In the Old Testament Michael is mentioned by name in the Persian context of the Book of Daniel. He is generally presented as the field commander of the Army of God. There Michael appears as "one of the chief princes" ( ) Michael who in Daniel's vision comes to the Lord's aid in his contest with the leader of Persia, and is also described there as the advocate of Israel and "great prince (or leader) who stands up for the children of your (Daniel's) people" ( , ). The Talmudic tradition rendered his name as meaning "who is like El ("God"—but literally "El's Likeness")" (compare the late prophet Micah), but according to Rabbi Simeon ben Lakish (AD 230–270), all the specific names for the angels were brought back by the Jews from Babylon, and many modern commentators would agree. The name title "Archangel" translated into the English language means: 'highest messenger'.

Much of the late Midrashic detail about Michael was transmitted to Christian mythology through the Book of Enoch, whence it was taken up and further elaborated. In late medieval Christianity, Michael, together with St George, became the patron saint of chivalry, and of the first chivalric order of France, the Order of Saint Michael of 1469. In the British honours system, a chivalric order founded in 1818 is also named for these two saints, the Order of St Michael and St George. St Michael is also considered in many Christian circles as the patron saint of the warrior. Police officers and soldiers, particularly paratroopers, regard him as their patron saint.

Roman Catholics refer to him as Saint Michael the Archangel and also simply as Saint Michael ("Saint" is a title meaning "holy", and is not meant to indicate that Michael is a human soul in heaven). Orthodox Christians refer to him as the Taxiarch ("Commander") Archangel Michael or simply Archangel Michael.