Jews have been involved in baseball since the sport's beginnings and have contributed to its evolution in many capacities, including players, agents, team owners, executives, umpires, broadcasters, and fans. In the United States, particularly, baseball played a large part in the assimilation of American Jews into American society at a time of rampant antisemitism and when Jews were immigrating to America to escape persecution. Today, it remains a very important part in Jewish American culture.
On the field, Jewish baseball players faced constant antisemitic heckles from opponents and fans, with many hiding their heritage to avoid discrimination in the league. Despite this, a number of Jewish players overcame such abuse and went on to become stars. Two such players, Hank Greenberg and Sandy Koufax, were both elected to the Baseball Hall of Fame and are widely considered to be amongst the most important and iconic players in baseball history. Similarly, off the field, Jews were involved deeply in the evolution of the game with executive Barney Dreyfuss, a Jewish immigrant who responsible for the founding of the World Series, the most prestigious event in baseball, and Marvin Miller who revolutionized the relationship between players and owners by unionizing players and helping usher in the era of free agency.