South Dakota Congressional Delegation: 1 Representative, 2 Senators
Last updated: 2026-10-19
House Delegation
1
U.S. Representative (at-large district)
1 Republican
Senate Delegation
2
U.S. Senators
2 Republicans
Delegation at a Glance
South Dakota sends 3 members to Congress: 1 representative in the House (1 Republican) and 2 Senators in the Senate (2 Republicans).
- With 1 U.S. Representative, South Dakota has the 45th-largest House delegation among the 50 states (tied with 5 other states).
- Members of South Dakota's delegation have served an average of 15.7 years in Congress.
State Highlights
- John Thune is South Dakota's longest-serving current member of Congress — in office since 1997 (29 years total).
- Mike Rounds is on the ballot for re-election in 2026.
Senators serve 6-year terms and representatives serve 2-year terms — see term end dates and election timing for each seat below.
Learn more about congressional term lengths, the Senate class schedule, or the upcoming 2026 election cycle.
2026 Election Picture for South Dakota
South Dakota's 2026 primary was held on June 2, 2026. Mike Rounds (Republican) is up for re-election to the U.S. Senate in 2026. All 1 of South Dakota's U.S. House seat is on the ballot in 2026, since House terms are two years. The general election is November 3, 2026.
For context on the 2026 map: in the 2024 presidential election Trump carried South Dakota by 29.3 points.
2026 is a midterm election year — it falls in the middle of the presidential term, so there is no presidential race on South Dakota's 2026 ballot. Every U.S. House seat nationwide is on the ballot every two years, and roughly a third of U.S. Senate seats — whichever class is next in rotation — are up in every congressional election, midterm or presidential.
Full South Dakota 2026 primary details · Election Day countdown · How midterm elections work
Voting in South Dakota
- Registration closes
- Likely closed (≈ Oct 19)
- Early voting opens
- ≈ Sep 18
- Election Day
- Tuesday, November 3, 2026
Dates are approximate — states count the days differently and county schedules vary. Confirm yours at vote.gov. See all registration deadlines or early voting dates by state.
Senate Class Breakdown
U.S. Senators serve staggered 6-year terms split into three classes, so a state's two Senate seats usually aren't on the ballot in the same year. South Dakota's two Senate seats are staggered across different classes.
The staggered system dates to the Constitution's framers, who wanted the Senate to change gradually rather than all at once — unlike the House, where every seat turns over every two years. Roughly one-third of the Senate's 100 seats (whichever class is next up) is on the ballot in any given election year, which is why only some states have a Senate race in any particular cycle.
- John Thune is Class 3 — next up for election in 2028.
- Mike Rounds is Class 2 — next up for election in 2026.
Learn more about the Senate class schedule.
Senators
Find your representative in South Dakota
South Dakota has a single at-large district, so every resident is represented by the same member of the U.S. House — listed below.
Representatives
1 total
How to Contact South Dakota's Delegation
Every member of Congress can be reached through the U.S. Capitol switchboard at (202) 224-3121 — ask the operator to connect you to any senator or representative by name, and you will be transferred directly to their office. Each member listed above also has a direct Washington, D.C. office line on their individual page, which staff typically answer during business hours (9am–5pm Eastern).
Congressional staff log the position of every caller, so calling or writing is one of the most direct ways for a constituent to weigh in on legislation before South Dakota's delegation votes on it.
Put South Dakota's delegation on your site
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Frequently Asked Questions
Who are South Dakota's senators?
As of 2026-10-19, South Dakota's U.S. Senators are John Thune (Republican) and Mike Rounds (Republican). Party breakdown: 2 Republicans. If you are studying for the citizenship test — "Who is one of your state's U.S. Senators now?" — either name is a correct answer for South Dakota.
How many representatives does South Dakota have?
South Dakota has 1 representative in the U.S. House as of 2026-10-19 — one at-large congressional district, the 45th-largest House delegation among the 50 states (tied with 5 other states). House seats are reapportioned among the states after each decennial census based on population.
When is South Dakota's 2026 primary?
South Dakota's 2026 primary was held on June 2, 2026. A U.S. Senate seat is on the ballot this cycle, and all 1 of South Dakota's U.S. House seat is also up for election in 2026, since House terms are two years.
Is South Dakota's congressional delegation Democratic or Republican?
As of 2026-10-19, South Dakota's entire congressional delegation — all 3 members — is Republican, giving Republicans unified control of South Dakota's seats in Congress.
Who represents South Dakota in Congress?
South Dakota is represented in Congress by 1 U.S. Representative in the House (1 Republican) and 2 U.S. Senators in the Senate. See the full current roster below, including term end dates and contact information.
How many senators does South Dakota have?
Two. Every state has exactly two U.S. Senators regardless of population, so South Dakota has the same Senate representation as every other state: John Thune (Republican) and Mike Rounds (Republican). House seats, by contrast, are apportioned by population — which is why South Dakota has 1 of them.
How many members of Congress does South Dakota have in total?
3 as of 2026-10-19 — 1 representative in the House plus 2 senators. Congress has 535 voting members in all (435 representatives and 100 senators), so South Dakota holds 0.6% of the seats.
When are South Dakota's senators up for reelection?
John Thune's seat (Class 3) is next on the ballot in November 2028; Mike Rounds's seat (Class 2) is next on the ballot in November 2026. Senators serve six-year terms in three staggered classes, so a state's two seats are never on the ballot in the same regular election.
How do I find out who represents me in South Dakota?
South Dakota has one at-large House seat, so its single representative and both senators represent everyone in the state. Enter your ZIP code or street address in the lookup at congresscountdown.com/who-is-my-representative to get your district and all three of your members of Congress.
How do I contact South Dakota's senators and representatives?
Every member card on this page lists the member's Washington office and phone number, and links to a profile with their official website. The Capitol switchboard, (202) 224-3121, connects to any Senate or House office by name. For what to say and which office to call — district office for casework, Washington office for legislation — see congresscountdown.com/info/contact-representative.