1878 in Ireland

Events

• 22 May – launch of the experimental powered submarine Holland I, designed by Irish-born John Philip Holland, at Paterson, New Jersey. Its performance impresses the American Fenian Brotherhood sufficiently to induce them to finance his continued experiments with a view to using such a machine against the British.
• 24 August – the narrow gauge Ballymena and Larne Railway starts passenger operations in County Antrim, the first on the Irish 3 ft narrow gauge.
• 9 October – St Mary's Cathedral, Tuam dedicated.
• 28 September – Intermediate Education Act passed: this will revolutionise Irish society, as it provides education to talented and hard-working boys and girls through "Exhibitions" worth up to $50. It particularly changes the position of women: by 1901 there will be 20,478 teachers in Ireland, 60% of them women, earning 80% of the male wage for the job.
• Mount St. Joseph Abbey, Roscrea established by Cistercian Trappist monks from Mount Melleray Abbey.
• Public Health (Ireland) Act 1878 introduces laws regarding sanitary districts.
• Mageough Home opens in Rathmines.

Arts and literature

• The Kerry Sentinel newspaper begins publication in Tralee.
• Oscar Wilde leaves Ireland permanently.

Sport

• Irish Cycling Association is established to administer cycling as the sport becomes popular throughout Ireland.

Births

• 8 January – Frederic Charles Dreyer, Royal Navy Admiral.
• 1 February – Thomás MacDonagh, nationalist, poet, rebel and Easter Rising leader.
• 14 February – Daniel Corkery, writer, teacher and Fianna Fáil Senator.
• 23 February – Pádraic Ó Máille, Sinn Féin MP and TD, Fianna Fáil Senator.
• 13 March – Patrick McCartan, Sinn Féin MP and TD, member of 1st Dáil, a founder member of Clann na Poblachta.
• 19 March – Michael James O'Rourke, soldier, recipient of the Victoria Cross for gallantry in 1917 at Hill 70 near Lens, France.
• 31 March – Jamesy Kelleher, Cork hurler.
• 11 April – Kathleen Clarke, née Daly, wife of Tom Clarke, Sinn Féin and later Fianna Fáil TD, Seanad member, first female Lord Mayor of Dublin.
• 17 April – Thomas Harvey, cricketer and rugby player.
• 3 June – Sinéad de Valera, née Ní Fhlannagáin, writer and wife of third President of Ireland, Éamon de Valera.
• 12 June – Geoffrey Taylour, 4th Marquess of Headfort, peer.
• 24 July – Edward Plunkett, 18th Baron Dunsany, writer and dramatist.
• 9 August – Eileen Gray, architect and designer.
• 15 August – Harry Corley, cricketer and rugby union international.
• 17 August – Oliver St. John Gogarty, physician, poet and writer.
• 24 August – Margaret Mary Pearse, Fianna Fáil TD and Seanad Éireann member, sister of Patrick Pearse.
• 28 October – Helena Concannon, Fianna Fáil politician and historian.
• 7 November – Margaret Cousins, née Gillespie, teacher, suffragist and Theosophist.
• 27 November – William Orpen, painter.
• 23 December – Francis Sheehy-Skeffington, suffragist, pacifist and writer.
• 30 December – Dick Walsh, Kilkenny hurler.

Deaths

• 22 March – Henry MacManus, artist
• 2 April – William Clements, 3rd Earl of Leitrim, nobleman and landowner.
• 22 September – Sir Richard John Griffith, 1st Baronet, geologist.
• 24 October – Paul Cullen, Cardinal and Catholic Primate of Ireland.
• 4 December – Richard Smyth, Presbyterian minister, academic and politician.
• 22 December – Patrick Mylott, soldier, recipient of the Victoria Cross for gallantry in 1857 in India.
• Full date unknown – Charles Anderson Read, journalist, novelist and anthologist.