Leonardo DiCaprio won an Oscar for Best Actor in 2004's "The Aviator".

The answer is false because Leonardo DiCaprio did not win an Oscar for Best Actor in 2004's "The Aviator." Although he was nominated for Best Actor for his role in the film, he did not receive the award that year. It was in fact Jamie Foxx who won the Best Actor Oscar in 2005 for his portrayal of Ray Charles in the film "Ray."