The 2026 elections put South Dakota’s single U.S. House seat on the ballot on November 3, 2026, alongside about a third of the U.S. Senate. House members serve two-year terms, so every district is contested in each even-numbered year. South Dakota’s single, at-large seat covers the entire state and is currently held by Dusty Johnson (R).
The at-large district
South Dakota’s 1 congressional district uses the same lines as in 2024, so the 2026 races run on those boundaries. The single district covers all of South Dakota, roughly the state’s entire population under the 2020 census. Statewide, South Dakota voted for Donald Trump by about 30 points in 2024, which sets the backdrop for its district races. How that statewide vote turns into seats depends on where the lines fall, which is why the map is contested as often as the candidates. South Dakota also elects two U.S. Senators, currently John Thune (R) and Mike Rounds (R). Senate terms run six years and the state’s two seats sit on different cycles. One of the two seats is up in 2026. Because the U.S. House is closely divided between the two parties, results in the most competitive districts, in South Dakota and elsewhere, can help decide which party controls the chamber for the next two years.
South Dakota kept its single at-large seat in the 2020 Census reapportionment, so one representative serves every resident of the state. With just one district, South Dakota has no congressional boundaries to redraw between censuses, and the at-large seat is on the ballot again in 2026.
Races to Watch
With one at-large seat, South Dakota does not have multiple House districts to compare. The statewide race is the whole story: in 2024 South Dakota voted for Donald Trump by about 29 points in 2024, and the seat is rated safe for the party that holds it. Voters across the state choose the same single member, so turnout anywhere in South Dakota counts toward the result, and the contest tends to track the state’s overall lean rather than any local swing.
Key Dates for South Dakota Voters
South Dakota holds its statewide primary on June 2, 2026. If no candidate for the U.S. House, U.S. Senate, or governor wins at least 35 percent of the vote, a runoff primary follows on July 28, 2026. The primary decides each party’s nominees for the U.S. House, U.S. Senate, and other offices, and the winners advance to the general election for its single House seat and the Senate seat on November 3, 2026. That general election falls on the same day across the country, and the results help set the makeup of the next Congress, which is seated in January 2027. Registration deadlines, mail-ballot rules, and early-voting dates are set by the state and can change, so confirm them with the South Dakota state election office before you plan to vote.
Find Your South Dakota District
Not sure which district you are in? Use the ZIP code lookup on our home page to find your South Dakota congressional district and see who represents you. For maps and the full list of the state’s seats, see the South Dakota congressional districts hub. For the Senate picture in every state, see U.S. Senators by State.
See also: 2026 Congressional Elections and U.S. Senators by State.
