Saint Patrick's Day or the Feast of Saint Patrick (Irish: Lá Fhéile Pádraig, "the Day of the Festival of Patrick") is a cultural and religious holiday celebrated on 17 March. It commemorates Saint Patrick (c. AD 387–461), the most commonly recognised of the patron saints of Ireland, and the arrival of Christianity in Ireland.^[2]

It is observed by the Catholic Church, the Anglican Communion (especially the Church of Ireland),^[3] the Eastern Orthodox Church and Lutheran Church. Saint Patrick's Day was made an official feast day in the early seventeenth century, and has gradually become a celebration of Irish culture in general.^[4]