Irwin Kostal (October 1, 1911 – November 23, 1994) was an American musical arranger of films and an orchestrator of Broadway musicals. 　　Born in Chicago, Illinois, Kostal attended Harrison Technical High School, but opted not to attend college, instead teaching himself musical arranging by studying the symphonic scores available at his local library. His first professional job was as a staff arranger for Design for Listening, an NBC radio show based in his hometown. Irwin was one of four children born to James and Emma Kostal in a Czech enclave of Chicago. His siblings James, Jerome and Violet all remained in the Chicago area.