Saint Apollonius (died around 186) is a 2nd century Christian martyr and apologist who is not to be confused with Apollinaris Claudius, an apologist of the same time frame.

Emperor Marcus Aurelius had softened the perseuction of Christians during his reign, and was replaced on his death by Commodus, who was a notoriously vicious ruler, yet he relaxed the persecution of Christians further. Apollonius converted to Christianity some time around the last years of Aurelius, and some time around 186 one of Apollonius's slaves, a man named Severus, formally accused his master of being Christian (and therefore of denying the emperor cult of Rome). Severus himself was executed, under a law of Aurelius stipulating that anyone accusing another of being a Christian

". . . if it were a delusion (as you assert) which tells us that the soul is immortal, and that there is a judgment after death and a reward of virtue at the resurrection, and that God is the Judge, we would gladly be carried away by such a lie as that, which has taught us to lead good lives awaiting the hope of the future even while suffering adversities."

His appeal was in vain and Apollonius was beheaded. His feast day in the Roman Catholic Church is April 18.