The Marshall County Courthouse is located in Marshalltown, Iowa, United States. The current building was completed in 1886 to replace an earlier building. The courthouse is a dominant landmark in downtown Marshalltown. It was individually listed on the National Register of Historic Places in 1972. In 2002 it was listed as a contributing property in the Marshalltown Downtown Historic District. It is the third building the county has used for a courthouse and county business.