- On 8 March, William Crotty, highwayman and outlaw of the Comeragh mountains in Co. Waterford, is tried at Waterford and later hanged, drawn and quartered, having apparently been betrayed by an associate named David Norris. According to legend, Crotty’s wife later commits suicide by leaping from a great height while being pursued by soldiers.
- Others who die in 1742 include Hugh Boulter, Church of Ireland archbishop of Armagh and political power-broker, and John Waller, member of parliament for Doneraile, of whom the lines were written: ‘Who is this hell-featured brawler? Is it Satan? No! ’tis Waller.’
- On 13 April Handel’s Messiah has its first public performance (conducted by the composer), at Neal’s Music Hall, Fishamble Street, Dublin, before an audience of 700.
- In August, Jonathan Swift is found to be ‘a person of unsound mind and memory and not capable of taking care of his person and fortune’ by a commission of lunacy composed of twelve Dublin tradesmen.
- Russborough House (Co. Wicklow), designed by Richard Castle, is built. The inland section of the Newry navigation, on which work had commenced in 1731, is completed: this is the first commercial canal in Britain or Ireland, and is originally intended to bring coal from the Tyrone coalfield to Dublin. Castle has also been involved in its design.
- Another famous architect, James Gandon, is born on 20 February. He will design some of Dublin’s most famous buildings, such as the Custom House and the Four Courts. Clotworthy Skeffington (2nd Earl of Massereene), who is born on 28 January, will spend nearly 20 years in debtors’ prisons in France until liberated by a mob in July 1789. The lawyer, orator and politician Walter Hussey Burgh is born on 23 August.