Events from the year 1955 in Ireland.

• President: Seán T. O'Kelly
• Taoiseach: John A. Costello (FG)
• Tánaiste: William Norton (Lab)
• Minister for Finance: Gerard Sweetman (FG)
• Chief Justice: Conor Maguire
• Dáil: 15th
• Seanad: 8th

• 6 January – The National Farmers' Association was formed during a meeting of 1,200 people in Dublin.
• 14 January – Tony O'Reilly was named in the Irish rugby squad for his first cap in an international match against France.
• 17 March (Saint Patrick's Day) – The Church of Ireland hallowed Trim Cathedral.
• 4 July – Denis Larkin was elected Lord Mayor of Dublin defeating 73-year-old Alfie Byrne.
• 21 July – The BBC brought its Divis television transmitter into service, marking the launch of a television service for Northern Ireland; the 35-kilowatt transmissions could also be readily received in much of Ireland.^[1]
• September – United States Senator John F. Kennedy and his wife Jacqueline visited Dublin for two days.^[2][3]
• 29 November – Publication of the Greyhound Industry Bill paved the way for the establishment of the greyhound board, Bord na gCon.
• 14 December – Ireland was admitted to the United Nations. Frederick Boland was appointed as its first ambassador.

• March – English language publication of Beckett's novel Molloy (in Paris and New York).
• 3 August – English language première of Samuel Beckett's play Waiting for Godot, directed by Peter Hall, at the Arts Theatre in London.
• 28 October – Irish première of Waiting for Godot at the Pike Theatre in Dublin.
• 12 December – The Cork Opera House at Emmet Palace was destroyed by fire.
• Sigerson Clifford published his poetry collection, Ballads of a Bogman.
• Michael Sheehy's modern history Divided We Stand: A Study In Partition was published.

• 15 January – Paddy Burke, Fine Gael Senator.
• 18 January – Fergus Martin, artist.
• 29 January – Liam Reilly, rock singer-songwriter (died 2021).
• 2 February – Dermot Ahern, Fianna Fáil TD for Louth and Cabinet Minister.
• 15 March – John McGuinness, Fianna Fáil TD for Carlow–Kilkenny.
• 27 March – Patrick McCabe, novelist.
• 29 March – Brendan Gleeson, actor.
• 1 April
  • Bobby Aylward, Fianna Fáil TD for Carlow–Kilkenny.
  • Joe O'Reilly, Fine Gael Senator.
• 7 April – Kevin Fennelly, Kilkenny hurler.
• 14 April – Simon Crowe, drummer with The Boomtown Rats.
• 17 April – Austin Brady, footballer.
• 24 April – Eamon Gilmore, Labour Party TD for Dún Laoghaire, leader of the Labour Party.
• 28 April – Mae Sexton, Progressive Democrats TD.
• 16 May – Páidí Ó Sé, Kerry Gaelic footballer and manager.
• 23 May
  • Mary Black, folk singer.
  • Luka Bloom, singer-songwriter and guitarist.
• 30 May – Colm Tóibín, novelist and critic.
• 20 June – Aonghus McAnally, broadcast producer and presenter, actor, guitar player, billiards champion and magician.
• 25 June - Paula Meehan, poet, playwright and teacher.
• 5 July – Sebastian Barry, playwright, novelist and poet.
• 6 July – William Wall, novelist, poet and short story writer.
• 20 July – Jem Finer, musician and composer.
• 16 August – James Reilly, Fine Gael TD for Dublin North and Minister for Health.
• 15 September – Brendan O'Carroll, comedian.
• 24 November – Jerry Holland, Munster rugby union player and coach (died 2022).
• 1 December – Pat Spillane, Kerry Gaelic footballer.
• 2 December – Joachim Kelly, Offaly hurler.
• 11 December – John Fenton, Cork hurler.
• 29 December – Pat Loughrey, Controller of BBC Northern Ireland, Director of BBC Nations and Regions and academic.

  Full date unknown

• John Allen, Cork hurler and manager.
• John Callinan, Clare hurler.
• Michael Gleeson, Tipperary hurler.
• Peter Wyse Jackson, Director of the National Botanic Gardens, Glasnevin, Dublin.
• Maighread Ní Dhomhnaill, traditional singer.
• Sean Power, Member of the States of Jersey.

• 22 January – Moira O'Neill, poet (born in 1864).
• February – John Dulanty, diplomat (born in 1883).^[4]
• 12 February – Thomas J. Moore, actor (born in 1883).
• 13 March – Evie Hone, painter and stained glass artist (born in 1894).
• 26 March – Thomas Farren, elected to Seanad Éireann in 1922 and 1931, member of the Labour Party.
• 4 May – Michael Colivet, manager Shannon Foundry, member of 1st Dáil (Anti Treaty), representing Limerick (born in 1882).
• 14 May – Robert Quigg, soldier, recipient of the Victoria Cross for gallantry in 1916 at the Battle of the Somme (born in 1885).
• 16 June – Stanislaus Joyce, scholar and writer, brother of James Joyce (born in 1884).
• 11 July – Frank Duffy, labour leader in the United States (born in 1861).
• 15 July – James Dolan, merchant, member of 1st Dáil (Pro Treaty), representing Leitrim (born in 1882).
• 16 July – May Guinness, writer (born 1863).
• 18 July – Billy McCandless, footballer and football manager (born in 1893).
• 14 September – Kathleen Lynn, physician and politician (born in 1874).
• 26 October – Michael Staines, Sinn Féin TD, member of 1st Dáil, first Commissioner of the Garda Síochána (born in 1885).