Oldham is a city in Kingsbury County, South Dakota, United States.

[6] According to the United States Census Bureau, the city has a total area of 0.25 square miles (0.65 km2), all land.

[7] The Loriks Peterson Heritage House is on the National Register of Historic Places.

47.7% of all households were made up of individuals, and 27.7% had someone living alone who was 65 years of age or older.

41.8% of all households were made up of individuals, and 25.3% had someone living alone who was 65 years of age or older.

About 12.5% of families and 20.3% of the population were below the poverty line, including 40.7% of those under the age of eighteen and 6.6% of those 65 or over.