I sang in a rock band when I was training as a lawyer. You know, not professional, we just did it for fun. We just did gigs all over Edinburgh and some in Glasgow and some at festivals.

In February 2012 Butler's publicist announced that Butler had completed a course of treatment for substance abuse of pain killers at a rehab-centre. Despite the film receiving mixed reviews Butler was praised for his performance. It’s the work and not the adulation that has proved to be the most fulfilling.

In 2007 Butler gained recognition through his portrayal of King Leonidas in the film 300. S. He also appeared as a voice actor in How to Train Your Dragon (2010).