Ipswich is a city in and county seat of Edmunds County, South Dakota, United States. The population was 954 at the 2010 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.
Ipswich is located at 45°26′42″N 99°1′49″W (45.445009, -99.030239).
According to the United States Census Bureau, the city has a total area of 1.34 square miles (3.47 km2), all of it land.
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/km2). There were 441 housing units at an average density of 329.1 per square mile (127.1/km2). 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.