The Fiestas del Pilar are an annual festival celebrated in the city of Zaragoza, Aragon, in honour of the patron saint of the city, the Virgen del Pilar. The week long festival takes place every year, usually, beginning the weekend of or before 12 October, and lasts until the following Sunday.

Our Lady of the Pillar is the name given to the Blessed Virgin Mary in the context of the traditional belief that Mary, while living in Jerusalem, supernaturally appeared to the Apostle James the Greater in AD 40 while he was preaching in what is now Spain. Those who adhere to this belief consider this appearance to be the only recorded instance of Mary exhibiting the mystical phenomenon of bilocation. Among Catholics, it is also considered the first Marian apparition, and unique because it happened while Mary was still living on Earth.