Woonsocket is a city in Sanborn County, South Dakota, United States. The population was 655 at the 2010 census. It is the county seat of Sanborn County.
Woonsocket was developed in 1883 as a railroad town because of its location at the junction on the Chicago, Milwaukee and Saint Paul Railroad. C.H. Prior, the superintendent of the railroad, named the town Woonsocket after his home town of Woonsocket, Rhode Island. The town was incorporated in 1888.
Woonsocket was known for an artesian well which was drilled in 1888. It was claimed that in its prime, the well flowed over 8,000 gallons per minute out of the six inch wide pipe. The well was capped off in 1906.
On June 24, 2003 an F3 tornado passed just east of town, it was one of 67 tornadoes that touched down on June 24, Holding a record for "Most tornadoes to touch down in one state in one day.
Woonsocket is located at 44°03′10″N 98°16′25″W.
According to the United States Census Bureau, the city has a total area of 0.79 square miles (2.05 km2), of which, 0.78 square miles (2.02 km2) is land and 0.01 square miles (0.03 km2) is water.
As of the census of 2010, there were 655 people, 287 households, and 168 families residing in the city. The population density was 839.7 inhabitants per square mile (324.2/km2). There were 318 housing units at an average density of 407.7 per square mile (157.4/km2).