Gaspar Milazzo (April 25, 1887 – May 31, 1930) was an Italian-American mobster and major organized-crime figure in Detroit, Michigan, during the Prohibition era.

Once powerful and now deceased New York Mafia Boss, Joe Bonanno wrote his 1983 autobiography, "A Man of Honor", that "Gaspar Milazzo and his cousin Stefano Magaddino were important men in the Brooklyn based "Castellammarese Clan".

After the death of Catalanotte in February 1930, Milazzo continued to be a high-ranking member of the Detroit crime family, although the actual extent of his power is under debate.

Some organized crime writers and authors claim that Milazzo was the successor to Sam Catalanotte, but if that was even true he had a very, very short reign.

West Side Mob leader Chet La Mare had sent word to East Side Mob leader Angelo Meli that he wanted a sitdown to discuss Mafia affairs and possibly end the feud, but Meli was no fool and he knew that it was not safe to meet with the treacherous La Mare.

What was not known to Milazzo and Meli was that powerful New York Mafia Boss Joe Masseria had begun to support Chet La Mare in his bid to take over the Detroit Mafia, which was something that would not please Milazzo who was a close associate of Angelo Meli and his two right-hand men, Joe Zerilli and Bill Tocco.