Thomas "Tommy" Bilotti was an American mobster who briefly served as underboss of the Gambino crime family in New York City. It was his promotion that helped trigger the 1985 assassination of Gambino boss Paul Castellano; Bilotti would end up killed as well as part of the assassination.

The Gambino crime family is an Italian-American Mafia crime family and one of the "Five Families" that dominate organized crime activities in New York City, within the nationwide criminal phenomenon known as the American Mafia. The group, which went through five bosses between 1910 and 1957, is named after Carlo Gambino, boss of the family at the time of the McClellan hearings in 1963, when the structure of organized crime first gained public attention. The group's operations extend from New York and the eastern seaboard to California. Its illicit activities include labor and construction racketeering, gambling, loansharking, extortion, money laundering, prostitution, fraud, hijacking, and fencing.