John S. Koliopoulos (Greek: Ιωάννης Σ. Κολιόπουλος) (Ioannis Koliopoulos in modern transliteration) was a Greek historian, born in the village of Votani, Kastoria in 1942.

He was the author of Plundered loyalties: Axis occupation and civil strife in Greek West Macedonia, 1941-1949,^[1] Brigands with a Cause^[2] and other books on Greek history, and co-author of Greece: A Modern Sequel with Thanos Veremis,^[3] Professor of Political History at Athens University and President of the board of ELIAMEP.

He was Professor Emeritus of Modern Greek History at Aristotle University of Thessaloniki.^[4]