The lawsuit filed Wednesday says the director of the forthcoming "X-Men: Days of Future Past" forced Michael Egan III into sex during parties in California and Hawaii when he was 17 in the late 1990s.
Singer's attorney Marty Singer says in a statement that the claims are absurd and defamatory. He says the lawsuit is an obvious attempt to get publicity ahead of the director's next movie.
"X-Men: Days of Future Past" is set for release May 23. It's the fifth film in the franchise.
The lawsuit is possible in Hawaii because of a state law that temporarily suspends the statute of limitations in sex abuse cases.