Knightley, who starred in "Atonement" and "Pirates of the Caribbean," told Britain's The Daily Telegraph the detailed media coverage of celebrities' private lives can be a distraction for audience members.
"I hate knowing too much when I'm going to the cinema and watching as a viewer," Knightley, 27, told the newspaper. "I don't want to know that the actor has just gone through a divorce. I don't want to know that the person is an alcoholic. It just gets in the way of my pleasure of watching the character."
Knightley said the celebrity press has blanketed Hollywood to the point that "everybody knows absolutely everything."
"I think it does change something, and not for the better," Knightley said. "I like watching films when I don't know anything about the people."