Gerald FitzMaurice FitzGerald (1335–1398), also known by the Irish Gaelic Gearóid Iarla, was the 3rd Earl of Desmond, in southwestern Ireland, under the first creation of that title, and a member of the Anglo-Norman dynasty of the FitzGerald, or Geraldines. He was the son of Maurice FitzGerald, 1st Earl of Desmond, by his third wife Aveline (Eleanor), daughter of Nicholas FitzMaurice, 3rd Lord of Kerry. He was half-brother to Maurice FitzGerald, 2nd Earl of Desmond.

Thomond, also known as the kingdom of Limerick, was a kingdom of Gaelic Ireland, associated geographically with present-day County Clare and County Limerick, as well as parts of County Tipperary around Nenagh and its hinterland. The kingdom represented the core homeland of the Dál gCais people, although there were other Gaels in the area such as the Éile and Eóganachta, and even the Norse of Limerick. It existed from the collapse of the Kingdom of Munster in the 12th century as competition between the Ó Briain and the Mac Cárthaigh led to the schism between Thomond and Desmond. It continued to exist outside of the Anglo-Norman-controlled Lordship of Ireland until the 16th century.