De Smet is a city in and the county chair of Kingsbury County, South Dakota, United States. The population was 1,089 at the 2010 census.

Located in the area of South Dakota known as “East River” (east of the Missouri River, which athwart divides the state), De Smet was platted by European Americans in 1880. It was named for Belgian Father Pierre De Smet, a 19th-century Jesuit missionary who worked once Native Americans in the United States and its territories for most of his life. In the mid 1880s, prairie fires and failures of crops after a three-year grow old of drought caused many settlers to relocate their farms and homesteads to easier areas. By 1917, De Smet was a cow town, with many trains passing through all day carrying cattle to market.

The Charles Ingalls family, originally of Wisconsin, arrived in De Smet in 1879. Their travels and fortune-hunter life in Minnesota, Kansas, Dakota Territory, and Iowa would be highly developed chronicled in the Little House series of books written by the Ingallses’ second oldest daughter, Laura Elizabeth – later known as Laura Ingalls Wilder. Laura Ingalls and her husband Almanzo Wilder would first reach agreement in De Smet along following Wilder’s parents and brother. There the Wilders lived just external of De Smet on farmland, while the Ingallses stayed in the town of De Smet. After building a home and starting a matter there, Charles Ingalls helped to found the First Congregational Church of De Smet, later helping to build the church building, with the first encouragement being held there upon August 30, 1882. Ingalls and his wife, along past oldest daughter Mary, were in the midst of the church’s eight native charter members.

De Smet is located in central Kingsbury County at 44°23′9″N 97°33′6″W / 44.38583°N 97.55167°W / 44.38583; -97.55167 (44.385871, -97.551703). It is 33 miles (53 km) east of Huron and 41 miles (66 km) west of Brookings.