Ipswich is a city in and county seat of Edmunds County, South Dakota, United States. The population was 928 at the 2020 census.

Ipswich was founded in 1883 as a stop on the Chicago, Milwaukee, St. Paul and Pacific Railroad. It was named after Ipswich, in England, perhaps via Ipswich, Massachusetts.

According to the United States Census Bureau, the city has a total area of 1.34 square miles (3.47 km), all of it land.

Historical population

Census	Pop.	Note	%±
1890	539		—
1900	397		−26.3%
1910	810		104.0%
1920	909		12.2%
1930	913		0.4%
1940	1,002		9.7%
1950	1,058		5.6%
1960	1,131		6.9%
1970	1,187		5.0%
1980	1,153		−2.9%
1990	965		−16.3%
2000	943		−2.3%
2010	954		1.2%
2020	928		−2.7%
U.S. Decennial Census

As of the census of 2010, there were 954 people, 402 households, and 249 families living in the city. The population density was 711.9 inhabitants per square mile (274.9/km). There were 441 housing units at an average density of 329.1 per square mile (127.1/km). The racial makeup of the city was 97.5% White, 0.1% African American, 0.9% Native American, 0.1% Asian, and 1.4% from two or more races. Hispanic or Latino of any race were 0.7% of the population.

There were 402 households, of which 29.6% had children under the age of 18 living with them, 51.7% were married couples living together, 7.5% had a female householder with no husband present, 2.7% had a male householder with no wife present, and 38.1% were non-families. 35.6% of all households were made up of individuals, and 17.9% had someone living alone who was 65 years of age or older. The average household size was 2.24 and the average family size was 2.91.

The median age in the city was 45.1 years. 23.3% of residents were under the age of 18; 6.3% were between the ages of 18 and 24; 20.3% were from 25 to 44; 27.3% were from 45 to 64; and 22.7% were 65 years of age or older. The gender makeup of the city was 49.8% male and 50.2% female.

As of the census of 2000, there were 943 people, 404 households, and 254 families living in the city. The population density was 719.3 inhabitants per square mile (277.7/km). There were 440 housing units at an average density of 335.6 per square mile (129.6/km). The racial makeup of the city was 98.52% White, 0.21% African American, 0.42% Native American, 0.11% Asian, 0.11% Pacific Islander, 0.21% from other races, and 0.42% from two or more races. Hispanic or Latino of any race were 0.64% of the population.

There were 404 households, out of which 29.7% had children under the age of 18 living with them, 54.0% were married couples living together, 7.7% had a female householder with no husband present, and 37.1% were non-families. 34.2% of all households were made up of individuals, and 20.8% had someone living alone who was 65 years of age or older. The average household size was 2.32 and the average family size was 3.01.

In the city, the population was spread out, with 27.4% under the age of 18, 5.3% from 18 to 24, 23.4% from 25 to 44, 19.3% from 45 to 64, and 24.6% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 92.1 males. For every 100 females age 18 and over, there were 84.1 males.

The median income for a household in the city was $33,073, and the median income for a family was $40,598. Males had a median income of $30,268 versus $16,413 for females. The per capita income for the city was $19,890. About 6.7% of families and 8.7% of the population were below the poverty line, including 6.2% of those under age 18 and 19.2% of those age 65 or over.

• Everett Hughes, United States military officer
• J.W. Parmley, South Dakota lawyer, legislator, and businessman

• List of cities in South Dakota

Media related to Ipswich, South Dakota at Wikimedia Commons