Bill Bailey (born Mark Bailey) is an English comedian, musician and actor.

Best known for his stand-up work, Bailey is a well known ffigure on many comedy panel shows, such as Never Mind the Buzzcocks, Have I Got News for You, Just a Minute and QI.

Bailey was listed by The Observer as one of the 50 funniest acts in British comedy in 2003. In 2007 and again in 2010, he was voted the 7th greatest stand-up comic on Channel 4's 100 Greatest Stand-Ups. He provided the voice of the sperm whale in the 2005 film The Hitchhiker's Guide to the Galaxy and has had parts in Burke and Hare, Nanny McPhee and the Big Bang and Skins