The plaintiff, called "John Doe" in the lawsuit, says the former Penn State assistant football coach approached him in a swimming pool and grabbed his genitals. He says he backed away and left the camp.
The lawsuit was filed Monday in federal court in Scranton. The defendants include Sandusky; his charity for troubled youths; Penn State; and former university officials.
Victims or accusers in the child sexual abuse scandal have filed at least four other lawsuits seeking monetary damages. Penn State has said it wants to settle the claims.
Sandusky was sentenced last week to at least 30 years in prison for sexually assaulting 10 boys.