Norwalk is a city in Warren County, with some small portions extending into Polk County, in the U.S. state of Iowa. The population was 8,945 at the 2010 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.
As of the census of 2010, there were 8,945 people, 3,261 households, and 2,472 families residing in the city. The population density was 832.9 inhabitants per square mile (321.6/km2). There were 3,450 housing units at an average density of 321.2 per square mile (124.0/km2). The racial makeup of the city was 96.9% White, 0.5% African American, 0.2% Native American, 0.6% Asian, 0.4% from other races, and 1.3% from two or more races. Hispanic or Latino of any race were 2.5% of the population.
There were 3,261 households of which 43.3% had children under the age of 18 living with them, 61.1% were married couples living together, 10.7% had a female householder with no husband present, 3.9% had a male householder with no wife present, and 24.2% were non-families. 20.2% of all households were made up of individuals and 6.3% had someone living alone who was 65 years of age or older. The average household size was 2.70 and the average family size was 3.13.
The median age in the city was 34.3 years. 30.2% of residents were under the age of 18; 6.9% were between the ages of 18 and 24; 29.6% were from 25 to 44; 24.6% were from 45 to 64; and 8.7% were 65 years of age or older. The gender makeup of the city was 48.4% male and 51.6% female.