Alpena (pronounced al-PEE'-nuh[6]) is a town in northeastern corner of Jerauld County, South Dakota, United States.

There were 124 housing units at an average density of 76.1 per square mile (29.4/km2).

27.3% of all households were made up of individuals, and 8.2% had someone living alone who was 65 years of age or older.

There were 122 housing units at an average density of 74.2 per square mile (28.6/km2).

28.3% of all households were made up of individuals, and 8.8% had someone living alone who was 65 years of age or older.

About 10.4% of families and 14.4% of the population were below the poverty line, including 18.5% of those under the age of eighteen and none of those sixty five or over.