1666 in Ireland

Events from the year 1666 in Ireland.

Incumbent

February – William Penn moves from London to Ireland to manage his father's estates. In May, he is involved in suppressing a mutiny in the English garrison at Carrickfergus.{{cite web|first=Mary K.|last=Geiter|title=Penn, William (1644–1718)|work=Oxford Dictionary of National Biography|publisher=Oxford University Press|year=2004|url=http://www.oxforddnb.com/view/article/21857|access-date=2012-08-31|doi=10.1093/ref:odnb/21857}} {{ODNBsub}}
The Parliament of Ireland meets for the last time until 1692 (apart from the Patriot Parliament of 1689).
Lord Maurice Roche of Castletownroche in County Cork loses his entire estate to Lieutenant Colonel John Widenham who receives the Castle as a reward for his loyalty to the Crown. The Castle of the Roches is thus renamed "Castle Widenham".{{cite web|title=History of Blackwater Castle|url=http://www.blackwatercastle.com/the-castle/history-of-blackwater-castle|publisher=Blackwater Castle|access-date=2012-08-31|archive-url=https://web.archive.org/web/20120904195528/http://www.blackwatercastle.com/the-castle/history-of-blackwater-castle|archive-date=2012-09-04|url-status=dead}}

Approximate date – Richard Pockrich, landowner, military commander and politician (d.1719)

August – Richard Burke, 6th Earl of Clanricarde, peer.
December 1 – Sir James Ware, historian, politician and Auditor general for Ireland (b.1594)
Sir Oliver Óge French, Galway merchant.
Raymond Caron, O.M.R., Franciscan friar and writer (b.1605)
Approximate date – Thomas Arthur, physician (b.1593)