The 1912 United States presidential election in South Dakota took place on November 5, 1912, as part of the 1912 United States presidential election. South Dakota voters chose seven representatives, or electors, to the Electoral College, who voted for president and vice president.
South Dakota was won by the 26th president of the United States Theodore Roosevelt (P–New York), running with governor of California Hiram Johnson, with 50.56% of the popular vote against the Princeton University President Woodrow Wilson (D–New Jersey), running with governor of Indiana Thomas R. Marshall, with 42.07% of the popular vote and the five-time candidate of the Socialist Party of America for President of the United States Eugene V. Debs (S–Indiana), running with the first Socialist mayor of a major city in the United States Emil Seidel, with 4.01% of the popular vote.
South Dakota was the only state in the 1912 United States presidential election to not have the sitting U.S president William Howard Taft on the ballot or as a write in (like in California) which prevented the spoiler effect from happening which gave the state to Theodore Roosevelt. With 50. 56% of the popular vote, South Dakota was also the only state in which Roosevelt won a majority of the vote as well as being his strongest state nationally.