Castlewarden (Irish: Caisleán Bhairnín)[1] is a townland, monastic site and former parish situated between Ardclough and Kill, County Kildare just off the N7 in Ireland.

The name Castlewarden appears to be derived from Warinus, Abbott of St Thomas’ Abbey in 1268 - Castellum Warin (Latin).

In 1377 John Leche, nephew of Ewa de L’Leche, wife of Hugh de Warin, and physician to Edward III, was grantee by patent of Castle Warin and other lands in Kildare.

Castlewarden House (which now forms the main building of Castlewarden Golf Club), a medieval earthwork complex, a motte and bailey, and a rectangular enclosure are all listed monuments under the Kildare development plan.

The earliest evidence of human habitation in the area was the discovery of a flint dated to 4800-3600BC, at Castlewarden below Oughter Ard Hill, a rare find on a dryland location.