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.

[citation needed] The club was founded in 1905.

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