| Eleutherius of Byzantium | |
| Patriarch Of: | Bishop of Byzantium |
| Enthroned: | 129 |
| Ended: | 136 |
| Predecessor: | Diogenes of Byzantium |
| Successor: | Felix of Byzantium |
| Religion: | Early Christianity |
Eleutherius (el|Ἐλευθέριος; died 136) was the bishop of Byzantium for approximately seven years (129–136 AD). He succeeded Bishop Diogenes. He was in office during the rule of Emperor Hadrian. His successor was Felix.[1]