In Old Chicago is a 1937 film directed by Henry King, written by Lamar Trotti and Sonya Levien and starring Tyrone Power, Don Ameche, Alice Brady and Brian Donlevy. It was nominated for six Oscars, of which it won two. The film tells the story of two rival O'Leary brothers during the great Chicago fire of 1871.

Jack and Dion O'Leary (Tyrone Power and Don Ameche) are brothers who were raised by their widow mother. Jack is the honest of the two brothers; Dion is roguish in nature. Dion aims to start his own entertainment empire, while Jack starts his own law firm. Both brothers are attracted by the same woman, singer (Alice Fay), who prefers Dion. As the two brothers move up in the world Jack becomes the city mayor, while Dion virtually controls all of the entertainment industry. Then, their mother knocks over a lantern, setting off the Great Chicago Fire of 1871. The brothers have to work together to fight this great threat to their city, uniting the two in the advent of rebuilding Chicago.

• Tyrone Power as Dion O'Leary

• Alice Fay as Belle Fawcett

• Don Ameche as Jack O'Leary

• Alice Brady as Molly O'Leary

• Andy Devine as Pickle Bixby

• Brian Donlevy as Gil Warren

• Phyllis Brooks as Ann Colby

• Tom Brown as Bob O'Leary

• Sidney Blackmer as General Phil Sheridan

"Zanuck's disaster film, part of cycle that also includes Ford's superior Hurricane, is not as entertaining as MGM's San Francisco, but by standards of the time, the set-pieces of crowds, riots, and cattle stampedes during the fire were deemed impressive. "—Emanuel Levy, EmanuelLevy.Comhttp://www.emanuellevy.com/search/details.cfm?id=9200

"Like San Francisco, events sort of just happen and allegiances just sort of shift around to stall time before the grand finale."—Eric Henderson, Slate Magazinehttp://www.slantmagazine.com/film/film_review.asp?ID=1736