Frederick is a town in northwestern Brown County, South Dakota, United States.

[6] Home to the annual Frederick Finn Fest, the town is part of the Aberdeen Micropolitan Statistical Area.

Frederick was a railway town platted and sold to pioneers by the Chicago, Milwaukee & St. Paul Railroad, which completed track into it on September 12, 1881.

Main Street and Railway Avenue intersect at the grid's core.

On July 2, 1921, a tornado swept through the downtown and "practically every building in the town was demolished", but only one resident was killed, after his home was torn from its foundation while he was trying to get his family into the storm cellar.

[7] According to the United States Census Bureau, the town has a total area of 0.39 square miles (1.01 km2), all land.

About 11.1% of families and 11.4% of the population were below the poverty line, including 13.4% of those under the age of eighteen and 18.8% of those 65 or over.