Grand River is a city in Decatur County, Iowa, United States. The population was 236 at the 2010 census.
Grand River got its start in the year 1881, following construction of the Humeston and Shenandoah Railroad through the territory.
Grand River is located at 40°49′8″N 93°57′45″W (40.818940, -93.962587) along the Thompson River (a tributary of the Grand River which is known throughout Iowa simply as the Grand River).
According to the United States Census Bureau, the city has a total area of 0.21 square miles (0.54 km2), all land.
At the 2010 census there were 236 people in 99 households, including 58 families, in the city. The population density was 1,123.8 inhabitants per square mile (433.9/km2). There were 128 housing units at an average density of 609.5 per square mile (235.3/km2). The racial makup of the city was 96.6% White, 0.4% Native American, 1.3% from other races, and 1.7% from two or more races. Hispanic or Latino of any race were 3.4%.
Of the 99 households 29.3% had children under the age of 18 living with them, 42.4% were married couples living together, 12.1% had a female householder with no husband present, 4.0% had a male householder with no wife present, and 41.4% were non-families. 35.4% of households were one person and 23.3% were one person aged 65 or older. The average household size was 2.38 and the average family size was 3.14.
The median age was 38 years.