Slough Feg (also known as The Lord Weird Slough Feg) is an American heavy metal band from Pennsylvania, formed in 1990 and currently based in the San Francisco Bay Area. Taking their name from the Celtic folklore-influenced comic book Sláine, the band released their self-titled debut album in 1996. Slough Feg combines influences from traditional heavy metal bands such as Iron Maiden, Brocas Helm, and Thin Lizzy, as well as English folk metal band Skyclad.

Slough Feg's 2003 album Traveller was a concept album based on the role-playing game of the same name. With the release of Atavism in 2005, the band officially shortened its name to Slough Feg. Guitarist Mike Scalzi maintains that the band always referred to itself this way internally, and the addition of "The Lord Weird" made it too difficult to find Slough Feg albums in stores (which alphabetized the CDs in inconsistent ways). Slough Feg most recently released New Organon in 2019.