1 January - Fastnet Rock lighthouse first lit.
21 January - The iron clipper RMS Tayleur runs aground on Lambay Island on her maiden voyage out of Liverpool with the loss of at least 300 of around 650 on board.
18 May - Catholic University of Ireland formally established in Dublin with John Henry Newman as first rector; lectures commence on 3 November.
21 June - During the First Battle of Bomarsund, Scarva-born Mate Charles Davis Lucas throws a live shell overboard, the earliest action to result in award of the Victoria Cross (in 1857).
20 September - During the Battle of the Alma, Elphin-born Sergeant Luke O'Connor saves the colours, the earliest action to result in award of the Victoria Cross to a soldier.
Quarrel between Tenant League and Archbishop Cullen; League appeals to Rome.
National Gallery of Ireland founded. Daniel Maclise paints The Marriage of Strongbow and Aoife which now hangs in the Gallery.
9 February - Edward Carson, Baron Carson, Irish Unionist leader, barrister and judge (died 1935).
25 March - John Le Hay, born John Healy, comic baritone (died 1926 resulting from traffic accident in London)
10 June - Sarah Grand, born Frances Elizabeth Bellenden Clarke, feminist author (died 1943 in England).
1 May - Percy French, civil engineer, songwriter, entertainer and artist (died 1920).
16 October - Oscar Wilde, playwright, novelist, poet (died 1900).
24 October - Horace Plunkett, politician, agricultural reformer and writer (died 1932).
Laurence Ginnell, nationalist, lawyer and politician, member of 1st Dáil (died 1923).
Bowman Malcolm, railway engineer (died 1933).
5 March - Thomas Devin Reilly, revolutionary, Young Irelander and journalist (born 1823).
6 March - Charles Stewart, 3rd Marquess of Londonderry, soldier, politician and nobleman (born 1778).
8 July - George Halpin, civil engineer (born c.1779).
8 August - Thomas Crofton Croker, antiquary (born 1798).
19 October - Henry Prittie, 2nd Baron Dunalley, politician (born 1775).
31 December - Nathaniel Clements, 2nd Earl of Leitrim, nobleman and Whig MP (born 1768).
Patrick O'Donoghue, journalist and Young Irelander.
1854 in Ireland Wikipedia