According to the New York Daily News, which compiled the list, people who made it to the dumb list are not necessarily low in IQ, as there are poor life choices, style slipups and mishaps under the influence to take into account.
The second dumbest Hollywood celeb is socialite Kim Kardashian, because of her much-publicised sex tape leak.
Third on the list is Spencer Pratt, for believing that his life on MTV's "The Hills" is reality.
At number four is Jeff Kwatinetz, the man who gave the green signal for Britney Spears' doomed MTV Video Music Awards performance.
Rounding the top five is actor Shia LaBeouf, for getting arrested while refusing to leave a Walgreens pharmacy.
Other Hollywood dumb-heads include reality television star Heidi Montag, singer Jessica Simpson, actor Mel Gibson, pop wreck Britney Spears, and Baywatch star David Hasselhoff.