Acacius may refer to:
Agathius, also known as Acacius of Byzantium (d. 303), Centurion of the Imperial Army. Feastday: May 8
Acacius of Amida (fl. 400–425), Mesopotamian bishop; feastday: April 9
Acacius of Sebaste, 4th century Armenian priest; feastday: November 27
Acathius of Melitene, 3rd century bishop, venerated by the Eastern Orthodox Church; feastday: March 31
Saint Acacius, leader of the Ten thousand martyrs; feastday: 22 June
Acacius the grammarian from Caesarea; friend of Libanius (314–394)
Acacius of Caesarea (d. 366), aka "the One-Eyed", bishop in Caesarea, opponent of St. Cyril of Jerusalem
Acacius of Beroea (d. 437), Syrian bishop
Patriarch Acacius of Constantinople (d. 489), Eastern Orthodox, active in the monophysitism controversy
Acacius (Nestorian Patriarch) (d. 496), Patriarch of the Church of the East
Acacius, father of Theodora (6th century) (500–548), empress of the Byzantine Empire
Acacius (proconsul), Byzantine proconsul of Armenia Prima (First Armenia), c. 536-539
Acacius (Alexandria), Byzantine military officer in Alexandria, c. 539-540
Acacius (curator), Byzantine imperial curator in the 560s
Acacius (son of Archelaus), Byzantine imperial representative, active c. 573
