The Church does not have an official stance on who the author is.
The author of the book of Revelation calls himself John (Rev. 1:1; 1:4). The only other clue to the author’s identity is that he states he received his visions while on the island of Patmos (Rev. 1:9).
Tradition has considered this person to be John the Apostle, the son of Zebedee. This tradition is attested to by Irenaeus (Against Heresies, V, 30) and Eusebius (Church History, IV). This tradition, however, is not universal. Dionysius, bishop of Alexandria, accepted the book of Revelation as inspired but did not accept that the author John was the same as John the Apostle (Church History, VII, 25). Also arguing against the Apostle John as the author is that several ancient lists of canonical books do not include it.
Complicating the matter is that while most accept the tradition that John the Apostle lived until 95, another strand of early Church tradition held that John the Apostle was martyred around the age of 70. Which tradition someone accepts will determine if he thinks John the Apostle would have been alive to write Revelation at the end of the first century.
While the book of Revelation and the Gospel of John share many similar themes, they differ dramatically in other literary categories.
While most modern scholars think the book of Revelation was written by a Christian prophet named John and not the apostle, the view that it was written by the apostle still exists.