1791 in Ireland

Events

• September – Wolfe Tone publishes Argument on Behalf of the Catholics of Ireland.
• 14 October – the Northern Whig Club, a group of nine Belfast Presbyterians, meets with Wolfe Tone and Thomas Russell and forms the Society of United Irishmen to press for liberal non-denominational parliamentary reform.
• 7 November – The Custom House in Dublin opens for business, having been completed under the supervision of James Gandon.

• The Grand Canal opens to a junction with the Barrow at Athy.
• The first bridge across the River Foyle at Derry, built by the American Lemuel Cox in wood, is opened to vehicular traffic.

  Births

• 6 March – John MacHale, Roman Catholic Archbishop of Tuam, Irish Nationalist and writer.
• 17 August – Richard Lalor Sheil, politician, writer and orator.
• 14 December – Charles Wolfe, poet.
• ;Full date unknown
• :*James Graham, soldier, commended for his gallantry during the Battle of Waterloo.

  Deaths

• 2 December – Henry Flood, statesman.
• ;Full date unknown
• :*George Bryan, businessman, statesman and politician in Pennsylvania.
• :*Robert Carver, artist.