| Date | | | |
| 5-May-1851 | | The canons and decrees of the Roman Catholic Synod of Thurles ratified by the Pope, and measures taken for the establishment of- a Roman Catholic University in Ireland. | |
| 1-Aug-1851 | | The Midland Great Western Railway opened for traffic to Galway. | |
| 2-Mar-1852 | | Departure from Dublin of His Excellency the Earl of Clarendon, Lord Lieutenant, consequent on the resignation of Lord John Russell's ministry. | |
| 10-Mar-1852 | | Arrival in Dublin of his Excellency the Earl of Eglinton and Winton, Lord Lieutenant of Ireland. | |
| 2-Apr-1852 | | Dr. Cullen elected successor to the late Archbishop Murray, by the parish priests of the Roman Catholic Archdiocese of Dublin. | |
| 1-Jun-1852 | | Electric Telegraph laid down between Holy-head and Dublin. | |
| 21-Jun-1852 | | £20,000 (subsequently increased by £6,000) , placed at the disposal of the Royal Dublin Society by Wm. Dargan, Esq., railway contractor, to be applied to an Exhibition of Irish Manufactures and other produce in Dublin, in 1853. | |
| 29-Jun-1852 | | Dr. Cullen enthroned as Roman Catholic Archbishop, in the Church of the Conception, Marlborough-st. | |
| 30-Sep-1852 | | The Dublin Royal Exchange opened by the Corporation as the City Hall. | |
| 14-Oct-1852 | | The Senate of the Queen's University in Ireland sits in Dublin Castle, for the purpose of conferring degrees, for the first time. | |