Apollonius (Greek Apollōnios) was a wealthy and educated Roman senator — possibly of Greek-Asian Hellenistic-Jewish family origin (the Acts of his martyrdom emphasize his classical Greek philosophical learning) — and one of the most prominent Christians of Rome in the late reign of Commodus (AD 180–192).
He was denounced as a Christian by one of his own household slaves. Under the Roman law of the period, denunciations of Christians required the death of the denouncer if proven false — and the denouncing slave was put to death first. But the Roman judicial authorities, now committed to proceed with the case, brought Apollonius before the senatorial tribunal. The proceedings — preserved in the partial-surviving Acta Apollonii in a Greek and an Armenian version (the Greek text was discovered in 1874 by François Combefis at Mount Athos) — record one of the longest and most theologically articulate trials in the early Christian martyrologial corpus.
Apollonius delivered before the assembled Roman Senate — and before the urban prefect Perennis — what amounted to a substantial extempore Christian apology, drawing on classical Greek philosophical sources to defend the rationality of Christianity. After the speech the Senate condemned him to death and he was beheaded around AD 185. The case is exceptional in that the Acts preserve a substantial portion of the actual senatorial-trial discourse — almost unique among 2nd-century martyrological documents.