John Palaiologos or Palaeologus () may refer to:
John Palaiologos (brother of Michael VIII) (1225/30–1274), general, brother of Byzantine emperor Michael VIII John Palaiologos (son of Andronikos II) (1286–1307), governor of Thessalonica John Palaiologos (Caesar) (1288/89–1326), governor of Thessalonica John II, Marquess of Montferrat (1321–1372), Marquess of Montferrat in 1338–1372 John V Palaiologos (1332–1391), Byzantine emperor in 1341–1391, with interruptions John III, Marquess of Montferrat (c. 1362–1381), Marquess of Montferrat in 1378–1381 John VII Palaiologos (1370–1408), Byzantine emperor in 1390 John VIII Palaiologos (1392–1448), Byzantine emperor in 1425–1448 John IV, Marquess of Montferrat (1413–1464), Marquess of Montferrat in 1445–1464 John Theodore Paleologus (1611–???), possibly a descendant of Thomas Palaiologos, Despot of the Morea