Black Irish are Irish who have dark hair and a dark complexion. They are possibly descendants of Moors, although there is an ongoing dispute about that.
The Black Irish are in contrast with the northern Irish who tend to have red hair and blue eyes and who are considered to be descendants of Norwegians, as in Eric the Red (Erik Thorvaldsson, c.950-1003).
The former Speaker of the House Paul Ryan (R-WI), who retired prematurely after losing control of the House to Democrats, has the look of the Black Irish. This is in contrast with the red-haired liberal Irishman former Rep. Joe Kennedy III (D-MA), who ran unsuccessfully in the Senate primary in 2020 and subsequently became a commentator for the Leftist CNN.
This term has a genealogical meaning outside of Ireland, contrast with its derogatory meaning for certain Protestant Irish in Northern Ireland.