Desmond Castle (Irish: Caisleán Deasmhumhan) is a tower house located in the town of Kinsale in County Cork, Ireland.

[3] The castle was built as the Customs House for Kinsale about the year 1500 by Maurice FitzGerald, 9th Earl of Desmond, following the grant of the customs of the port of Kinsale to the Earls of Desmond by King Henry VII in 1497.

[4] Presumably there must have been an earlier structure on the site as the 1st Earl was Captain of Desmond Castle.

[5] In January 1747, a fire broke out, killing 54 of the prisoners.

In 1791, the castle was donated by James Kearney MP to the town of Kinsale, and it was subsequently used as a town gaol till 1846, and during the Irish Famine as a workhouse.