Pitt's movie "Burn After Reading" is No. 1 at the U.S. box office. The actor and his partner, Hollywood actress Angelina Jolie, have said they won't consider marrying until gay marriage is legal throughout the entire United States.
"Because no one has the right to deny another their life, even though they disagree with it, because everyone has the right to live the life they so desire if it doesn't harm another and because discrimination has no place in America, my vote will be for equality and against Proposition 8," Pitt said in a statement to Usmagazine.com.
"It is our hope that others in the entertainment industry will step up and match Brad Pitt's heroic commitment to quality and defeating Prop. 8," political strategist Chad Griffin said in a statement released to the entertainment news Web site.