"Who Knows Who" is a collaboration song by English alternative rock band Muse and English hip hop artist Mike Skinner. Not originally intended for official release, an early version of the song leaked onto several Muse internet forums in August 2008. The song was officially released as the B-side to the 7" vinyl edition of the single "Uprising" on 7 September 2009. The lyrics were written by Skinner and the music was written by Muse's Matthew Bellamy.