The locals of Knock, County Mayo, Ireland report their having seen an apparition of the Virgin Mary. The apparition is later named "Our Lady of Knock" and the spot transformed into a Catholic pilgrimage site.

Knock is a village in County Mayo, Ireland.

The Sanctuary of Our Lady of Knock, commonly referred to as Knock Shrine, is a Roman Catholic pilgrimage site and national shrine in the village of Knock, County Mayo, Ireland, where locals claimed to have seen an apparition in 1879 of the Blessed Virgin Mary, Saint Joseph, Saint John the Evangelist, angels, and Jesus Christ.

Mary was a first-century Jewish woman of Nazareth, the wife of Joseph and the mother of Jesus. She is an important figure of Christianity, venerated under various titles such as virgin or queen, many of them mentioned in the Litany of Loreto. The Eastern and Oriental Orthodox, Catholic, Evangelical Lutheran, Reformed, Anglican, Methodist and Baptist churches believe that Mary, as mother of Jesus, is the Mother of God. The Church of the East historically regarded her as Christotokos, a term still used in Assyrian Church of the East liturgy. She has the highest position in Islam among all women and is mentioned numerous times in the Quran, including in a chapter named after her. She is also revered in the Baháʼí Faith and the Druze Faith.

The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institutions and has played a prominent role in the history and development of Western civilization. The Church consists of 24 sui iuris (autonomous) churches, including the Latin Church and 23 Eastern Catholic Churches, which comprise almost 3,500 dioceses and eparchies around the world, each overseen by one or more bishops. The pope, who is the bishop of Rome, is the chief pastor of the church.