The suit filed by a Cook County resident names Brother Christopher McCartney as the culprit in the alleged molestation at St. Rita of Cascia High School.
McCartney, who died in 2002, was a member of the Augustinian order, which runs St. Rita, an all-boys school.
The suit names the Roman Catholic Archdiocese of Chicago as defendant on the grounds Cardinal Francis George and other church officials failed to investigate complaints about McCartney.
The Chicago Tribune said the defendant, whose name was not revealed, only remembered his alleged encounters with McCartney a year ago. The man said in written statement provided by his attorney he was "still haunted by the torture I endured as a teen."