Sidney R. Korshak (June 6, 1907 – January 20, 1996) was a labor lawyer and "fixer" for businessmen in the upper echelons of power and the Chicago Outfit in the United States. His reputation as the Chicago mob's man in Los Angeles made him one of Hollywood's most fabled and influential fixers. His partnership with Chicago mobsters led him to be named "the most powerful lawyer in the world" by the FBI. A book on Korshak's life "Supermob: How Sidney Korshak and His Criminal Associates Became America's Hidden Power Brokers" was released in 2006.
He was born into a Jewish family, with four siblings, in Chicago's West Side Lawndale neighborhood, on June 6, 1907. His father was a wealthy Chicago contractor. His younger brother, Marshall Korshak, became a longtime Chicago politician, city treasurer and state senator. Sidney attended Herzl Grammar School, the University of Wisconsin–Madison and obtained his law degree from the DePaul University College of Law.
His law practice brought him into contact with many mobsters, such as Al Capone, Frank Nitti, Sam Giancana, Tony Accardo and Moe Dalitz. His services were used by the upper ranks of both legitimate and illegitimate business in the United States.
Korshak numbered among his friends many Hollywood celebrities and leading figures in the entertainment industry, including MCA/Universal chiefs Jules C. Stein and Lew Wasserman, entertainment lawyer Paul Ziffren (the driving force behind bringing the 1984 Olympics to Los Angeles), MGM chief Kirk Kerkorian, Gulf+Western founder Charles Bluhdorn, Frank Sinatra, Ronald Reagan, William French Smith (labor attorney and future United States Attorney General), Edmund "Pat" Brown, Edmund "Jerry" Brown, future Governor of California Gray Davis, producer Robert Evans, Warren Beatty, Barron Hilton and Hugh Hefner.
Korshak was highly successful in the field of labor consulting and negotiations, and his client list included Hilton Hotels, Hyatt Hotels, MGM, Playboy, MCA/Universal, and Diner's Club. One of his clients was Jimmy Hoffa, notorious head of the International Brotherhood of Teamsters; Korshak was heavily involved in the Teamsters' west coast operations during a time when organized labor was at the peak of its activity. He was identified as an associate of the Los Angeles crime family under boss Nick Licata in the 1970s.
Korshak was an attorney for various elements of the Chicago Outfit. Korshak bought the J.P. Seeburg Corporation and immediately after the company stock rose from $35 to $141.50 a share. He then sold 143,000 shares to pivotal figures in the stock market like Bernard Cornfield, who owned the FOF Property Fund, in Switzerland. Korshak received $5 million from the deal.
Sidney Korshak married Beatrice and had three children, Harry, Stuart and Katy. The Korshaks' primary residence was a mansion in Beverly Hills for many years, with a secondary home in Palm Springs.
It was Korshak who suggested actress Jill St. John to Eon Productions for the James Bond film, Diamonds Are Forever.
Sidney Korshak died on January 20, 1996, without ever having a criminal conviction against him (or even an indictment, according to his New York Times obituary). Marshall Korshak predeceased his brother by one day.