South Dakota is a state in the high plains of the northern Middle West. It is named after the Lakota (Sioux) American Indian tribe. South Dakota was admitted to the Union on November 2, 1889. North Dakota was admitted on the same day.

South Dakota is bordered to the north by North Dakota, to the south by Nebraska, to the east by Iowa and Minnesota, and to the west by Wyoming and Montana. It is one of the six states of the Frontier Strip.

USS South Dakota was named in honor of this state.