John VIII
John VIII may refer to:
- Pope John VIII, Pope from 872 to 882
 - Antipope John VIII, antipope in 844
 - John VIII bar Abdoun, Syriac Orthodox Patriarch of Antioch (944-1033)
 - John VIII of Constantinople, Patriarch of Constantinople (1010-1075)
 - Pope John VIII of Alexandria, Coptic Pope from 1300 to 1320
 - John VIII Palaiologos, Byzantine Emperor (1392–1448)
 - John VIII, Count of Harcourt, 1398–1424
 - John VIII, Count of Vendôme, 1426–1477
 - John VIII, Archbishop of Antivari, d. 1571
 - John VIII, Count of Nassau-Siegen, 1583–1638
 - The mythical Pope Joan, in some versions of her legend
 
See also
- John 8, the eighth chapter of the Gospel of John