The Priory of All Hallows (or Priory of All Saints) was a monastic foundation just outside Dublin, Ireland.
All Hallows was founded in 1166 by Diarmait Mac Murchada shortly before his deposition as by King of Leinster. It was situated east of the walled city in an area known as "Hoggin Green" or "Hogges Green" or "Le Hogges". It was an Araosian (Augustinian) foundation, with canons regular. The priory was one of the most important, and over time became one of the wealthiest, religious establishments in the vicinity of Dublin, along with the Priory of St John the Baptist (Thomas Street), the Priory of the Holy Trinity and St. Mary's Abbey, Dublin (as well as the more remote foundations such as Grace Dieu Abbey).
Four years after founding the priory, Mac Murchada, by then restored to his lands by his Cambro-Norman allies, landed an invasion at the Steine and captured the walled city from the ruling Hiberno-Norse dynasty. The priory survived the invasion and a period of prosperity followed.
As part of the Reformation in Ireland, the Crown dissolved the priory. In 1538, the buildings and lands were granted, for a Crown head rent of 4 pounds, 3 shillings and a halfpenny, to the mayor and corporation of Dublin on behalf of the citizens.
Archbishop Loftus asked the mayor to grant the All Hallows lands, then generating a rent of only 20 pounds a year for the city, for the use of a college and when this was done, he employed Henry Ussher to appeal to Elizabeth I of England for a charter for a college and a licence for the land, which was granted in December 1591. This new foundation became Trinity College, Dublin of which Archibishop Loftus became first Provost.