Castlewellan GAC (also known as St Malachy's GAC, or in Irish, CLG Naomh Maolmhaodhóg, Caisleán Uidhilín) is a Gaelic Athletic Association club in Castlewellan, County Down, Northern Ireland. The club promotes the Gaelic games of hurling, Gaelic football, camogie and other cultural and social pursuits. The club was founded in 1905.

• Down Senior Club Football Championship
• List of Gaelic Athletic Association clubs

• Official Castlewellan GAA Club website
• Official Down County website
• Official An Riocht GAA Club website (archived 2018)