Quartus was an early Christian saint, a presbyter, and a bishop who lived in Athens. Identified in the Bible as a fellow believer alongside Erastus, he is traditionally counted among the Seventy Disciples. After receiving grace on Pentecost, he traveled to preach the gospel, including in the city of Magnis where he baptized new converts. Though he faced severe torture and stoning in Athens, he survived these persecutions and eventually died in Berytus.