Eleutherius (died 620) was the exarch of Ravenna from 615 until 619. A eunuch, he succeeded John I as exarch. Early in his reign, nearly the entire exarchate was unstable. In Ravenna, there was obvious discontent with the Byzantines; in Naples, a certain John of Conza separated the city from the exarch's control. Eleutherius arrived in Ravenna and immediately put to death "all who had been implicated in the death of Exarch John and the judges of the State." Then, after making a courtesy visit to Pope Deusdedit, Eleutherius marched on Naples, and captured that city, killing the rebel John and his supporters. However, soon after the Lombards threatened war. Eleutherius was able to sue for peace, promising a yearly tribute.