Aristobulus of Britannia is a saint of Roman Catholicism and Orthodox Christianity. He was named as one of the Seventy Disciples and the first bishop in Roman Britain by Hippolytus of Rome.
Pseudo-Hippolytus lists "Aristobulus, bishop of Britain" among the seventy disciples.
Aristobulus may be mentioned in the New Testament in the Epistle to the Romans (: "...Salute them which are of Aristobulus' household") although this may mean members of the household of the late Aristobulus IV. According to Lionel Smithett Lewis, the writings of St Dorotheus, Bishop of Tyre AD 303, assert that he is the one saluted by Paul in the Epistle to the Romans.
Orthodox tradition says he was the brother of the Apostle Barnabas, of Jewish Cypriot origin. Like Barnabas, he accompanied Saint Paul on his journeys. He was one of the assistants of Saint Andrew, along with Urban of Macedonia, Stachys, Ampliatus, Apelles of Heraklion and Narcissus of Athens. On his missionary journey to Britain, he stopped to preach to the Celtiberians of northern Hispania. Catholic tradition identifies Aristobulus with Zebedee, father of James and John.