List of United States senators from South Dakota

Current delegation

John Thune (R)

Mike Rounds (R)

South Dakota was admitted to the Union on November 2, 1889, and elects U.S. senators to class 2 and class 3. Its current U.S. senators are Republicans John Thune (since 2005) and Mike Rounds (since 2015). Karl E. Mundt is South Dakota's longest-serving senator (1948–1973). South Dakota is one of 15 states alongside California, Colorado, Florida, Georgia, Hawaii, Idaho, Louisiana, Maine, Massachusetts, Minnesota, Missouri, Nevada, Pennsylvania, and Utah to have a younger senior senator and an older junior senator. South Dakota's class 3 seat also holds the distinction of having a future Senate Majority Leader (John Thune) defeat and succeed a former Majority Leader (Tom Daschle).