Marco Reginelli (January 2, 1897 – May 26, 1956), also known as "Small Man", was an Italian-American New Jersey mobster who became underboss of the Philadelphia crime family and operated a famous nightclub in Atlantic City, New Jersey.
He first settled in an Italian-American community in Penns Grove, New Jersey, with many neighbors from Valle San Giovanni and Teramo.
In the 1930s, Reginelli moved to Camden, New Jersey, where he became a member of the Cosa Nostra.
Reginelli eventually extended his influence to the resort area of Atlantic City.
It is alleged that Reginelli may have had a hand in financing the 500 Club, a nightclub run by Paul "Skinny" D'Amato in Atlantic City from 1946 to 1973.