After the English Reformation (an uneven process between 1536 and 1564 but at St Patrick's effective from about 1537), St Patrick's became an Anglican (Church of Ireland) church.
In the 1530s some images within the cathedral were defaced by soldiers under Thomas Cromwell, and neglect led to collapse of the nave in 1544.
The conventionally-flexible style of the Archbishop of Dublin Hugh Curwen is instructive; he was a follower firstly of Henry's non-reformed church in the 1530s, then of Edward VI's full-blown Protestantism c. 1550, then accepting his appointment as archbishop during Queen Mary's reversion of the church to Roman Catholicism in 1555, and continued to serve as the archbishop, using the Anglican rite from 1559, under Queen Elizabeth until 1567.

Under King Edward VI, St Patrick's Cathedral was formally suppressed and the building demoted back to the status of parish church.
On 25 April 1547, a pension of 200 marks sterling was assigned to "Sir Edward Basnet", the dean, followed, some months later, by pensions of £60 each to Chancellor Alien and Precentor Humphrey, and £40 to Archdeacon Power.
The silver, jewels, and ornaments were transferred to the dean and chapter of Christ Church.
The King designated part of the building for use as a court house, the cathedral grammar school was established in the then vicar's hall and the deanery given to the archbishop, following the transfer of the Archbishop's Palace to the Lord Deputy of Ireland.
In 1549, it was further ordered that the walls be repainted and inscribed with passages from the scriptures.

In 1555 a charter of the joint monarchs Philip and Mary restored the cathedral's privileges and initiated restoration and a late document of Queen Mary's reign, a deed dated 27 April 1558, comprises a release or receipt by Thomas Leverous, the new dean, and the chapter of St Patrick's, of the "goods, chattels, musical instruments, etc.",
belonging to the cathedral, and which had been in the possession of the dean and chapter of Christ Church.
It was during this reign that the patronal festival of the Blessed Virgin Mary was last celebrated (in 1558).

Following the ejection of the Catholic chapter of canons in 1559, the Catholic community continued in the 1560s–1570s at least to go on nominating canons and the principal dignitaries to St Patrick's.

In 1560, one of Dublin's first public clocks was erected in "St Patrick's Steeple".
After the English Reformation (an uneven process between 1536 and 1564 but at St Patrick's effective from about 1537), St Patrick's became an Anglican (Church of Ireland) church. In the 1530s some images within the cathedral were defaced by soldiers under Thomas Cromwell, and neglect led to collapse of the nave in 1544. The conventionally-flexible style of the Archbishop of Dublin Hugh Curwen is instructive; he was a follower firstly of Henry's non-reformed church in the 1530s, then of Edward VI's full-blown Protestantism c. 1550, then accepting his appointment as archbishop during Queen Mary's reversion of the church to Roman Catholicism in 1555, and continued to serve as the archbishop, using the Anglican rite from 1559, under Queen Elizabeth until 1567.
Under King Edward VI, St Patrick's Cathedral was formally suppressed and the building demoted back to the status of parish church. On 25 April 1547, a pension of 200 marks sterling was assigned to "Sir Edward Basnet", the dean, followed, some months later, by pensions of £60 each to Chancellor Alien and Precentor Humphrey, and £40 to Archdeacon Power. The silver, jewels, and ornaments were transferred to the dean and chapter of Christ Church. The King designated part of the building for use as a court house, the cathedral grammar school was established in the then vicar's hall and the deanery given to the archbishop, following the transfer of the Archbishop's Palace to the Lord Deputy of Ireland. In 1549, it was further ordered that the walls be repainted and inscribed with passages from the scriptures.
In 1555 a charter of the joint monarchs Philip and Mary restored the cathedral's privileges and initiated restoration and a late document of Queen Mary's reign, a deed dated 27 April 1558, comprises a release or receipt by Thomas Leverous, the new dean, and the chapter of St Patrick's, of the "goods, chattels, musical instruments, etc.", belonging to the cathedral, and which had been in the possession of the dean and chapter of Christ Church. It was during this reign that the patronal festival of the Blessed Virgin Mary was last celebrated (in 1558).
Following the ejection of the Catholic chapter of canons in 1559, the Catholic community continued in the 1560s–1570s at least to go on nominating canons and the principal dignitaries to St Patrick's.
In 1560, one of Dublin's first public clocks was erected in "St Patrick's Steeple".
St Patrick's Cathedral, Dublin