Denison is a city in Crawford County, Iowa, United States, along the Boyer River, and located in both Denison Township and East Boyer Township.

As of the census of 2020,[12] there were 8,373 people, 2,853 households, and 1,882 families residing in the city.

There were 3,089 housing units at an average density of 471.8 per square mile (182.2/km2).

Hispanic or Latino persons of any race comprised 49.6% of the population.

29.7% of all households were made up of individuals, 16.2% had someone living alone who was 65 years old or older.

At the 2010 census there were 8,298 people, 2,816 households, and 1,866 families living in the city.

There were 2,968 housing units at an average density of 453.8 per square mile (175.2/km2).

As of the census[14] of 2000, there were 7,339 people, 2,674 households, and 1,756 families living in the city.

There were 2,837 housing units at an average density of 458.3 per square mile (177.0/km2).

According to a New York Times article, 20% of Denison's high-school age children were nonwhite in 2005, compared to approximately 50% of kindergarteners.

Sites in Denison listed on the National Register of Historic Places include: Denison is governed by a mayor and a five-member city council[16][17] The Denison Mayor is the chief executive officer of the city and presiding officer of the city council.