Marshalltown is a city located in Marshall County Iowa. It is also the county seat of Marshall County. With a 2020 population of 26,030, it is the 18th largest city in Iowa and the 1483rd largest city in the United States . Marshalltown is currently declining at a rate of -1.21% annually and its population has decreased by -5.52% since the most recent census, which recorded a population of 27,552 in 2010. Marshalltown reached it's highest population of in . Spanning over 19 miles, Marshalltown has a population density of 1,350 people per square mile.
The average household income in Marshalltown is $62,565 with a poverty rate of 14.79%. The median rental costs in recent years comes to $685 per month, and the median house value is $94,300. The median age in Marshalltown is 36.7 years, 35.9 years for males, and 37.5 years for females.