Saint Sebastian (died c. 288 AD) was an early Christian saint and martyr. According to Christian belief, he was killed during the Roman emperor Diocletian's persecution of Christians. He is commonly depicted in art and literature tied to a post or tree and shot with arrows. Despite this being the most common artistic depiction of Sebastian, he was, according to legend, rescued and healed by Irene of Rome. Shortly afterwards he went to Diocletian to warn him about his sins, and as a result was clubbed to death. He is venerated in the Catholic and Orthodox Churches.

The details of Saint Sebastian's martyrdom were first spoken of by 4th-century bishop Ambrose of Milan (Saint Ambrose), in his sermon (number 22) on Psalm 118. Ambrose stated that Sebastian came from Milan and that he was already venerated there at that time. Saint Sebastian is a popular male saint, especially among athletes.