Sidney Olcott (eigentlich John Sidney Alcott; * 20. September 1873 in Toronto, Ontario; † 16. Dezember 1949 in Hollywood, Los Angeles, Kalifornien) war ein kanadischer Filmproduzent, Filmregisseur, Schauspieler und Drehbuchautor. ()
John Sidney Olcott was a Canadian-born film producer, director, actor and screenwriter. After making a number of very successful films for the Kalem studio, including "Ben Hur" (1907) with its dramatic chariot race scene, Olcott became the company's president and was rewarded with one share of its stock.