Feohanagh-Castlemahon (Irish: An Fheothanach – Caisleán Uí Mhathúna) is a Gaelic Athletic Association club located in the parish of Mahoonagh, County Limerick, Ireland.

Feohanagh/Castlemahon won the 2011 West Junior A Hurling Championship defeating Dromcollogher/Broadford in the final in Feenagh on 15 October 2011 on a scoreline of 2–10 to 0–08.

In 2014 Feohanagh/Castlemahon won the County Junior Championship hurling final beating Na Piarsaigh in a replay on a scoreline of 0-20 to 0-09.

In football in 2013 they were beaten by Glin 0-08 to 0–07 in the West final, but like the hurling that year, the West runners-up won the county final as Castlemahon won on a score line of 1–08 to 1–07, securing intermediate status for 2014.

They went on to defeat Drom-Inch of Tipperary and Coolmeen of Clare but were beaten in the Munster Junior Football Championship Final by Keel of Kerry by 0–14 to 0–04.