The 2016 United States presidential election in South Dakota was held on November 8, 2016, as part of the 2016 United States presidential election in which all 50 states plus the District of Columbia participated. South Dakota voters chose electors to represent them in the Electoral College via a popular vote pitting the Republican Party's nominee, celebrity Donald Trump, and running mate Indiana Governor Mike Pence against Democratic Party nominee, former Secretary of State Hillary Clinton and her running mate, Virginia Senator Tim Kaine.

Pennington County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 109,222, making it the second most populous county in South Dakota. Its county seat is Rapid City. The county was created in 1875, and was organized in 1877. It is named for John L. Pennington, fifth Governor of Dakota Territory, who held office in 1875 when the county was formed.