Jewish-American organized crime (sometimes called the Jewish Mob, Jewish Mafia, Kosher Mafia, or the Kosher Nostra —a play on words of Cosa Nostra), emerges during the late 19th and early 20th centuries.

In the late 19th century in New York City, Monk Eastman operates a powerful Jewish gang that competes with Italian and Irish gangs, notably Paul Kelly's Five Points Gang, for control of New York City's underworld.In the early 1920s, stimulated by the economic opportunities of the Roaring Twenties and later, Prohibition, organized crime figures such as Arnold Rothstein are controlling a wide range of criminal enterprises.

According to crime writer Leo Katcher, Rothstein "transformed organized crime from a thuggish activity by hoodlums into a big business, run like a corporation, with himself at the top."

Rothstein is allegedly responsible for fixing the 1919 World Series.

The largely Jewish-American gang known as Murder Inc., as well as mobsters such as Meyer Lansky, gain significant influence within the Italian American Mafia.

For decades after, Jewish-American mobsters continue to work closely and at times compete with Italian-American organized crime.