Numerous early Christian martyrs were named Valentine.[14] The Valentines honored on February 14 are Valentine of Rome (Valentinus presb. m. Romae) and Valentine of Terni (Valentinus ep. Interamnensis m. Romae). Valentine of Rome was a priest in Rome who was martyred in 269 and was added to the calendar of saints by Pope Gelasius I in 496 and was buried on the Via Flaminia. The relics of Saint Valentine were kept in the Church and Catacombs of San Valentino in Rome, which "remained an important pilgrim site throughout the Middle Ages until the relics of St. Valentine were transferred to the church of Santa Prassede during the pontificate of Nicholas IV". The flower-crowned skull of Saint Valentine is exhibited in the Basilica of Santa Maria in Cosmedin, Rome. Other relics are found at Whitefriar Street Carmelite Church in Dublin, Ireland.

Valentine of Terni became bishop of Interamna and is said to have been martyred during the persecution under Emperor Aurelian in 273. He is buried on the Via Flaminia, but in a different location from Valentine of Rome. His relics are at the Basilica of Saint Valentine in Terni (Basilica di San Valentino). Jack B. Oruch states that "abstracts of the acts of the two saints were in nearly every church and monastery of Europe." The Catholic Encyclopedia also speaks of a third saint named Valentine who was mentioned in early martyrologies under date of February 14. He was martyred in Africa with a number of companions, but nothing more is known about him. Saint Valentine's head was preserved in the abbey of New Minster, Winchester, and venerated.

February 14 is celebrated as St. Valentine's Day in various Christian denominations; it has, for example, the rank of 'commemoration' in the calendar of saints in the Anglican Communion. In addition, the feast day of Saint Valentine is also given in the calendar of saints of the Lutheran Church. However, in the 1969 revision of the Catholic Calendar of Saints, the feast day of Saint Valentine on February 14 was removed from the General Roman Calendar and relegated to particular (local or even national) calendars for the following reason: "Though the memorial of Saint Valentine is ancient, it is left to particular calendars, since, apart from his name, nothing is known of Saint Valentine except that he was buried on the Via Flaminia on February 14.