The suit said Ramales and other staffers didn't get their proper share of a gratuity charge that the Upper East Side restaurant automatically collected from parties with six or more diners.
Ramales, of the Bronx, also said he worked more than 40 hours per week without getting overtime.
A manager at the restaurant, Chris Russell, called the lawsuit baseless. He said staff members received every dime of their tips, and busboys were paid well over the legal minimum wage.
Publicists for Timberlake did not immediately respond to e-mail messages Friday night. The lawsuit also names two other partners in the restaurant; Russell said he couldn't immediately provide phone numbers for them.
Lawsuits alleging similar labor law violations have been filed against several other New York City restaurants in recent years.
Timberlake, 27, became a star as part of the boy band 'N Sync and has since become a best-selling solo artist. He also has appeared in the films "Alpha Dog" and "Black Snake Moan" and voiced a character in "Shrek the Third."