Headkase is a hard rock/metal band from Brisbane, Australia formed in 2001 and known for their theatrical and energetic stage shows (often including circus-themed costumes, masks and facepaint).

Notable for combining many different musical styles (metal, jazz, techno, salsa, swing, and circus music, among others) the band's sound is frequently compared to acts like Mr. Bungle and Dog Fashion Disco, and has always been described by fans and reviewers as "circus-metal", a term which the band have chosen to use themselves as a description of their music.

They have supported Killing Joke (UK), Skinlab (USA) and Jerk along with Blood Duster, Devolved and Testeagles, as well as performances at festivals including Overcranked 2006 and Rapid 2002 and 2005.

Headkase released a demo/EP titled The Beginning in 2001, followed by their full-length studio album The Worm County Circus in early 2009, which was mastered by Dave Neil (whose other mastering work includes releases by Devolved, The Butterfly Effect, Melodyssey and Kate Miller-Heidke).