Norwalk is a city in Polk and Warren counties in the U.S. state of Iowa. The population was 6,884 at the 2000 census. The city is part of the Des Moines–West Des Moines Metropolitan Statistical Area and is located just south of the Des Moines International Airport. It is the hometown of actors Brandon Routh, star of the film Superman Returns, and Jason Momoa, star of the television show Stargate: Atlantis.