Celebrities are starting to be attracted to Twitter in ever increasing numbers. If you think about it, it makes sense. As a celebrity you are typically misrepresented in the media, and while many have taken to blogging to speak direct to fans, Twitter makes this even easier.
Sorting out the real celebrities from fake celebrities is an issue, but less of a problem than you might think. It doesn’t take too long before fakers are found out and celebrities have a vested interest in revealing the fakers once they become aware of them, which usually isn’t long.
Jack Schofield over at the Guardian posted a list recently which was missing links in the original post. I’ve gone ahead and added the links to make it more convenient and added several new celebs. I’ll continue to add new celebrities as I become aware of them.
There’s a brand new site which covers celebrities on Twitter from a news / blogging angle (think Perez Hilton / DListed / TMZ meets Twitter). It’s a great way to stay on top of the major celebrity on Twitter news stories.

List of Celebrities on Twitter

Alan Carr (link) Comedian
Andy Murray (link) Tennis player
Arnold Schwarzenegger (link) Actor/politician
Ashton Kutcher (link)American Actor
Barack Obama (link) US President
Brea Grant (link) American actress, Heros
Britney Spears (link) Pop singer
David Mitchell (link) British comedy actor (Doubt as to authenticity – this may be the real one)
Demi Moore (link)American actress
Elijah Wood (link) Hollywood actor
Felicia Day (link) American actress, Web video maven
Graham Linehan (link) TV director (Father Ted, IT Crowd etc)
Greg Grunberg (link) Matt in Heroes
James Kyson Lee (link) Korean American actor, Heroes
Jimmy Carr (link) Comedian
Jimmy Fallon (link) American comedian, actor etc, SNL
John Cleese (link) Python etc
John Hodgman (link) Actor etc; PC in TV ads
Jonathon Ross (link) Broadcaster
Kevin Smith (link) Movie maker etc
Kerry Rhodes (link) NFL defenceman
Krishnan Guru-Murthy (link) British News Anchor
Lance Armstrong (link) cyclist
Levar Burton (link) Star Trek actor
Luke Wilson (link) American actor
Mark Moore (link) British musician / producer
MC Hammer (link) Rapper
Natalie Gulbis (link) Golfer
Neil Gaiman (link) English author
Penn Jillette (link) Magician
Peter Serafinowicz (link) British actor, etc
Rainn Wilson (link) American actor
Richard Branson (link) Virgin
Robert Llewellyn (link) English actor, Red Dwarf etc
Seth MacFarlane (link) Family Guy creator
Shaquille O’Neal (link) basketball player, rapper etc
Snoop Dogg (link) Rapper etc
Stephen Fry (link) British actor and geek
Will Carling (link) Rugby player
Wil Wheaton (link), Star Trek actor etc
Yoko Ono (link) Japanese artist
UK Politics
Andy Reed (link)
David Lammy (link)
George Foulkes (link)
Tom Harris (link)
Tom Watson (link)
Boris Johnson (London Mayor) (link)
10 Downing Street (link)
Houses of Parliament (link)
US politics
Al Gore (link)
Joe Trippi (link)
Karl Rove (link)
Ross Perot (link)
You may also be interested in Brands that are on Twitter, Bands that are on Twitter, and Executives on Twitter.