1800 in Ireland

Events

• 28 February – United Irishman Roddy McCorley is executed in Toomebridge for his part in the Irish Rebellion of 1798.
• April – United Irish Uprising of Irish soldiers stationed at St. John's, Newfoundland, with the British Army is dispersed.
• 2 July & 1 August – Acts of Union 1800: the linked Union with Ireland Act 1800, an Act of the Parliament of Great Britain, and Act of Union 1800, an Act of the Parliament of Ireland, are passed by the respective legislatures, to unite the Kingdom of Ireland and Kingdom of Great Britain into the United Kingdom of Great Britain and Ireland, with effect from 1 January 1801. The latter Act, drafted at Derrymore House, achieves its majority of 43 in the Irish House of Commons partly through the bribing of former opponents by the award of peerages and honours.
• 1 August – foundation stone of the new King's Inns in Dublin laid, James Gandon being commissioned as the architect.
• 12 August – start of construction of the Military Road across the Wicklow Mountains.
• Dr. John Milner Barry introduces vaccination in Cork.

  Arts and literature

• Maria Edgeworth's first extended work of fiction, the pioneering historical novel with an Irish setting Castle Rackrent, is published anonymously in London.

  Births

• 6 January – Anna Maria Hall, novelist.
• 16 January – Robert Bell, journalist and writer.
• 26 February – John Baptist Purcell, Roman Catholic Archbishop of Cincinnati.
• 17 March – James Patrick Mahon, Irish nationalist politician and international mercenary.
• 18 March – Harriet Smithson, actress.
• 17 June – William Parsons, 3rd Earl of Rosse, astronomer and builder of the "Leviathan of Parsonstown".
• July – Richard Quain, anatomist and surgeon.
• 14 October – John Hogan, sculptor.
• ;Full date unknown
• :*George Forrest, recipient of the Victoria Cross for gallantry during the Indian Rebellion of 1857 at Delhi, India.
• :*Anthony Lefroy, Conservative Party MP for Longford in the Parliament of the United Kingdom.

  Deaths

• 28 February – Roddy McCorley, United Irishman and a leader of the Irish Rebellion of 1798.
• Richard Geoghegan, agriculturalist.
• Approximate date
• *Thomas Conway, soldier.
• *Eibhlín Dubh Ní Chonaill, noblewoman and poet, composer of Caoineadh Airt Uí Laoghaire.