Pionius of Smyrna was a Christian priest and hieromartyr who lived in the third century. He is primarily remembered for his steadfast refusal to perform pagan sacrifices during a period of Roman persecution, likely under the reign of Emperor Decius around 250 AD. According to historical accounts, he faced trial and torture in Smyrna, where he delivered a defense of his faith to a diverse crowd before being executed by fire. He is honored as a saint in several Christian traditions.