John of Patmos (also called John the Revelator, John the Divine, John the Theologian; Ancient Greek: Ἰωάννης ὁ Θεολόγος, romanized: Iōannēs ho Theologos) is the name traditionally given to the author of the Book of Revelation. Revelation 1:9 states that John was on Patmos, an Aegean island off the coast of Roman Asia, where according to some biblical historians, he was exiled as a result of anti-Christian persecution under the Roman emperor Domitian.
Christian tradition has considered the Book of Revelation's writer to be the same person as John the Apostle, though some Christian scholars since medieval times have separated the disciple from the writer of Revelation. A minority of ancient clerics and scholars, such as Eusebius (d. 339/340), recognize at least one further John as a companion of Jesus, John the Presbyter.