Arnold Rothstein (January 17, 1882 – November 6, 1928), nicknamed "The Brain", was an American racketeer, gangster, businessman and gambler who became a kingpin of the Jewish Mob in New York City. Rothstein was widely reputed to have organized corruption in professional athletics, including conspiring to fix the 1919 World Series. He was also a mentor of future crime bosses Lucky Luciano, Meyer Lansky, Frank Costello, Bugsy Siegel and numerous others.
Rothstein is credited with "transform[ing] organized crime from a thuggish activity by hoodlums into a big business run like a corporation," gaining notoriety as the person who first realized the lucrative opportunities afforded by Prohibition and "understood the truths of early 20th century capitalism (giving people what they want) and came to dominate them." His notoriety inspired several fictional characters based on his life, portrayed in contemporary and later forms of media, including the character Meyer Wolfsheim in F. Scott Fitzgerald's novel The Great Gatsby (1925).
Rothstein refused to pay a large debt resulting from a fixed poker game and was murdered in 1928.