1645 in Ireland

Events from the year 1645 in Ireland.

• Monarch: Charles I

• Irish Confederate Wars: Lismore town and castle are sacked by a force of the Irish Confederacy commanded by Lord Castlehaven.
• January 20–March 18 – Siege of Duncannon: Confederate general Thomas Preston takes Duncannon.
• April 23 (Saint George's Day) – English Civil War: one hundred and fifty Irish soldiers bound for service with King Charles I of England are captured at sea by Parliamentarians and killed at Pembroke in Wales.
• October 27 – Catholic Bishop Malachy Ó Caollaidhe is killed by Scottish forces during a Confederate expedition to Sligo.
• The Society of Jesus establishes a school in Galway, the predecessor of Coláiste Iognáid.

• Henry Burkhead's closet drama Cola's Fury, or Lirenda's Misery, based on the Irish Rebellion of 1641, is written.^[1]
• John Colgan's Acta Sanctorum Hiberniae is published in Leuven.

• Richard III de Bermingham, Anglo-Irish landowner (b. 1570)
• Peter Martin (STP), Dominican.
• Muiris mac Torna Ó Maolconaire, scribe and poet.