1845 in Ireland

Events

• 18 February – Devon Commission reports to the British government on the poor living conditions of the Irish population: "in many districts their only food is the potato".
• September–December – African American abolitionist Frederick Douglass makes a speaking tour of Ireland.
• 9 September – previously unknown potato blight strikes the potato crop: start of the Great Famine.
• 1 October – Wesley College founded.
• 31 October-1 November: an emergency meeting of the Cabinet of the United Kingdom votes against Peel on the distribution of relief in Ireland, considering it would call the Corn Laws into question.
• 9-10 November – Peel orders the secret purchase of £100,000 worth of maize and meal from the United States for distribution in Ireland.
• 15 November – scientific commissioners report that half the Irish potato crop has been destroyed by the blight.
• 20 November – a relief commission for Ireland first meets.
• 5 December – unable to persuade his Cabinet to repeal the Corn Laws in the face of the Great Famine, Peel tenders his resignation as Prime Minister of the United Kingdom to Queen Victoria but is reinstated days later when Lord John Russell is unable to form a government.
• 30 December – Queen's Colleges of Belfast, Cork and Galway are incorporated.
• Bessbrook in County Armagh is established as a model village by Quaker linen manufacturer John Grubb Richardson.
• Construction begins of the "Leviathan of Parsonstown", a telescope built by William Parsons, 3rd Earl of Rosse.
• Work completed on the building of Crumlin Road Gaol in Belfast.

  Arts and literature

• Charles Lever's novel The O'Donoghue: a tale of Ireland fifty years ago is published in Dublin and St Patrick's Eve in London.

  Births

• 23 March – John T. Browne, Mayor of Houston, Texas.
• 6 April – Edward Hardman, geologist.
• 10 June – David Dickson Rogers, politician in Ontario.
• 17 June – Emily Lawless, writer.
• 1 July – James M. Bell, United States Army soldier, awarded the Medal of Honor in 1876 during the .
• 4 July – Thomas John Barnardo, philanthropist.
• 23 November – Charlotte Grace O'Brien, political and social activist, writer and plant collector.
• ;Full date unknown
• :*James Carey, Fenian and informer.
• :*Eglantyne Louisa Jebb, social reformer.
• :*James O'Kelly, nationalist politician and journalist, Irish Parliamentary Party MP.
• :*John Pinkerton, Irish Parliamentary Party MP.

  Deaths

• 22 February – William Wellesley-Pole, 3rd Earl of Mornington, politician.
• 28 April – James Graham, soldier, commended for his gallantry during the Battle of Waterloo.
• 13 July – Johnston Drummond, early settler of Western Australia, botanical and zoological collector.
• 16 September – Thomas Osborne Davis, lawyer and writer, author of the song "A Nation Once Again".
• 17 December – Armar Lowry-Corry, 3rd Earl Belmore, politician and High Sheriff.