Felix of Byzantium was a second-century prelate who served as the bishop of Byzantium for five years. Holding his position from 136 to 141, he succeeded Eleutherius and was eventually followed by Polycarpus II. His tenure occurred during the Roman Empire under the leadership of emperors Hadrian and Antoninus Pius. Recognized as a saint and hierarch, he is commemorated in both Catholic and Orthodox traditions.