Pitt's donation marks the largest thus far to the anti-Prop. 8 campaign by an A-list celebrity.

"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," the actor said in a statement.

Pitt's donation marks the largest thus far to the anti-Prop. 8 campaign by an A-list celebrity.