Brad Pitt has donated $US100,000 ($A126,800) to fight California's November ballot initiative that would overturn the state Supreme Court decision legalising same-sex marriage.
It is the first time voters will be asked to decide the issue in either California or Massachusetts - the states where gays have won the right to wed through rulings by state courts.
"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 on Wednesday.
The ballot question known as Proposition 8 essentially will ask voters to prohibit the practice of same-sex marriage, which was approved this year by the California Supreme Court.
Trevor Neilson, Pitt's political and philanthropic adviser, told The Associated Press that Pitt was surprised that his colleagues in the entertainment industry had not donated more money to support the battle against Proposition 8.
Earlier in the week, Pitt and Angelina Jolie announced they had donated $US2 million ($A2.54 million) to help fight HIV/AIDS and tuberculosis in Ethiopia.
Yahoo!7
