1620 in Ireland

Incumbent

• Monarch: James I

  Events

• County Longford is planted by English and Scottish landowners, with much of the O'Farrell lands being confiscated and granted to new owners.
• Bangor, County Down, is granted the status of a port by King James I of England.

  Honours

• 13 October – the Blundell Baronetcy is created in the Baronetage of Ireland in favour of Francis Blundell, Vice-Treasurer and Receiver-General of Ireland.
• 10 November – the Parsons Baronetcy, of Bellamont in the County of Dublin, is created in the Baronetage of Ireland in favour of William Parsons, 1st Baronet of Bellamont|William Parsons], Surveyor General of Ireland.
• 12 December – the title of Earl of Antrim is created in the Peerage of Ireland in favour of Randal MacDonnell, Viscount Dunluce.
• The titles of Earl of Cork and Viscount of Dungarvan are created in the Peerage of Ireland in favour of Richard Boyle, Lord Boyle.
• The title of Viscount Grandison is created in the Peerage of Ireland in favour of Oliver [St John, 1st Viscount Grandison|Oliver St John], Lord Deputy of Ireland.

  Births

• Peter [Talbot (bishop)|Peter Talbot], Archbishop of Dublin (Roman Catholic)
• Approximate date – Redmond O'Hanlon, outlaw

  Deaths

• February 15 – James [Archer (Jesuit)|James Archer], Jesuit
• July 10 – John Boyle, Bishop of Cork, [Cloyne and Ross]