John (fl. 537–553), the nephew of the rebel Vitalian, was an East Roman (Byzantine) general under Justinian I (r. 527–565), who was active in the Gothic War in Italy and against the Gepids in the western Balkans. He was married to Justina, the daughter of Justinian's cousin Germanus.
John appears as a character in the time travel novel Lest Darkness Fall, by L. Sprague de Camp.
- Bury, John Bagnell (1958). History of the Later Roman Empire: From the Death of Theodosius I to the Death of Justinian, Volume 2. Mineola, New York: Dover Publications, Inc. ISBN 0-486-20399-9.
- Martindale, John Robert; Jones, Arnold Hugh Martin; Morris, J., eds. (1992). The Prosopography of the Later Roman Empire, Volume III: A.D. 527–641. Cambridge, United Kingdom: Cambridge University Press. pp. 652–661. ISBN 978-0-521-20160-5.