Events from the year 1910 in Ireland.
- 8 January – Sinéad Flanagan marries Éamon de Valera in Dublin.
- 21 February – Irish Unionist members of the Westminster Parliament elect Sir Edward Carson as party leader, replacing Walter Long.
- 23 February – St Patrick's College, Maynooth, becomes a recognised college of the National University of Ireland.
- May – Irish Countrywomen's Association founded as the Society of the United Irishwomen by a group of educated and largely Protestant women in Bree, County Wexford "to improve the standard of life in rural Ireland through Education and Co-operative effort".
- June – Bridget Dowling elopes to London with Alois Hitler, Jr., a kitchen porter at the Shelbourne Hotel, Dublin, and half-brother to Adolf.
- July – James Connolly returns to Ireland from the United States.
- August – first passenger flight in Ulster: Harry Ferguson pilots Miss Rita Marr.
- 29 August – the Aero Club of Ireland holds its inaugural aviation meeting at Leopardstown Racecourse.
- 11 September – English-born actor-aviator Robert Loraine makes an aeroplane flight from Wales across the Irish Sea but lands some 200 feet (60 metres) short of the Irish coast in Dublin Bay.
- 20 October – RMS Olympic is launched at the Harland & Wolff shipyard in Belfast. At 45,324 gross tons, she is the largest ship afloat. Her sister ship RMS Titanic will be launched in sixteen months' time.
- 3 December – Sir Edward Carson and James Campbell are re-elected unopposed as Unionist Members of Parliament for Trinity College Dublin.
- Non-subscribing Presbyterian Church of Ireland created by merger of the Presbytery of Antrim and Remonstrant Synod of Ulster.
- Lilian Bland builds and flies her own biplane glider, the first built in Ireland, from Carnmoney Hill, soon afterwards fitting an engine and making her first powered flight in late August.