"Sport" Sullivan (November 2, 1870 – April 6, 1949) was an American bookmaker and gambler from Boston, Massachusetts who helped to initiate the 1919 Black Sox Scandal.

[4] At Sullivan's suggestion, Gandil recruited several teammates to intentionally lose the games.

Sullivan met with noted organized crime boss Arnold Rothstein, who agreed to bankroll the fix for $80,000.

[6] If Sullivan did testify, it would probably expose the fact that Rothstein had been the one providing the money for the Black Sox players to fix the Series.

Sullivan reportedly was paid by Rothstein to flee to Mexico so that he would not go to Chicago to testify in front of the Grand Jury.