Knock (Irish: An Cnoc, meaning The Hill – but now more generally known in Irish as Cnoc Mhuire, "Hill of (the Virgin) Mary") is a village in County Mayo, Ireland.

Knock is also a civil parish in the ancient barony of Costello.

It is notable as the location of Knock Shrine - a Marian shrine and place of pilgrimage. According to Catholic beliefs, Mary, mother of Jesus, Saint Joseph and Saint John the Evangelist appeared to witnesses in the village on 21 August 1879. There is international skepticism of this event due to the age of the witnesses and the lack of evidence supporting the event. In the 20th century, Knock became one of Europe's most visited shrines to the Virgin Mary, along with Lourdes and Fatima. It was a focus of peace pilgrimages in Ireland during the Second World War, when the faithful prayed for peace. One and a half million pilgrims visit the shrine annually.

In 1979, on the centenary of the apparition, Pope John Paul II visited the shrine. On 26 August 2018, Pope Francis visited the basilica while in Ireland for the 9th World Meeting of Families.

Knock comes from the Irish word "cnoc" meaning hill, historical evidence shows the village had been named that as far back as 1625. The Irish language name was changed to "Cnoc Mhuire" meaning the hill of the Virgin Mary after the visions. The parish and village of Knock is sometimes referred to historically and in Lewis' 1837 topographical dictionary as Knockdrumcalry (Cnoc Droma Chálraighe) meaning "hill of the ridge of the Cálraighe".

The civil parish of Knock covers 45 townlands. Thirty five of the townlands are in the barony of Costello. The remaining 10 townlands along the central western boundary of the parish are in the neighbouring barony of Clanmorris. Knock is located five miles from the town of Claremorris (one of the major market towns of the early 19th century) and is between Claremorris and Ballyhaunis.

Monsignor James Horan (1911–1986) became parish priest of Knock in 1963. During his tenure, he oversaw the construction of a new basilica church with a capacity for 10,000 worshipers. "Our Lady, Queen of Ireland" was consecrated in 1967. Monsignor Horan was also involved in the construction of the nearby Ireland West Airport. He was a leading advocate in issuing an invitation to Pope John Paul II to visit Knock in 1979 to commemorate the centenary of the Marian apparition.

The local primary school is Knock National School, built in 1966.

The local soccer club is Kiltimagh Knock United F.C. established in 2002. Their ground, CMS Park, is situated in Cloonlee on the Knock/Kiltimagh Road, 3 km from the village. There is no other sports club located in the parish area and players from the village often play for neighbouring clubs.

Ireland West Airport, which is located 19 km (12 miles) to the north of the village on the N17 road near Charlestown, was opened by Monsignor James Horan on 30 May 1986 and has been an important tourism boost for the village and shrine.

• Knock basilica, The Basilica of Our Lady, Queen of Ireland
• List of towns and villages in Ireland
• Marian apparition

• Peter H. Görg, Das Wunder von Knock - Die Erscheinung der Jungfrau Maria in Irland in Zeiten sozialer Not, Illertissen 2010.
• Tom Neary, I Saw Our Lady, Knock, 156 p.
• John Scally, I Was Cured at Knock - The extraordinary story of an extraordinary woman, Knock 2005, 127 p.
• Ethna Kennedy (Ed.), Judy Coyne Providence My Guide. The heroic force in the Knock Shrine story, Knock, 254 p.
• The Custodians of Knock Shrine (Ed.), Knock – Heiligtum Unserer Lieben Frau. Leitfaden für Wallfahrer, Knock.
• Fr. Berchmans Walsh OCSO, Knock Mary's International Shrine of the Lamb of God, Knock, 16 p.
• Sean Egan & Tom Neary (Ed.), Knock Parish Church - 1828–2006, Knock 2006, 24 p.
• Knock Shrine Society (Ed.), Knock Shrine Annual, Knock 1938ff.
• The Custodians of Knock Shrine (Ed.), Knock Shrine. A Pilgrim's Guide Book, Englisch, Französisch, Deutsch, Spanisch, Italienisch, Knock, 26 p.
• Fr. Hubert OFMCap., Knock - Vision of Hope, Knock, 36 p.
• Tom Lane CM, Reflecting at Knock Before our Merciful Lamb, Knock, 127 p.
• Msgr. Michael Walsh, The Apparition at Knock - A Critical Analysis of Facts and Evidence, Knock, 1955
• Msgr. Michael Walsh, The Glory of Knock, Knock 2000, 51 p.
• Donal Flanagan (Hrsg.), The Meaning of Knock, Knock 1997.
• Mary Francis Clare Cusack, Three Visits to Knock, New York 1882.

• Knock Shrine
• Knock, Co Mayo
• Ireland-West Airport, Knock