South Dakota's 3rd legislative district is one of 35 districts in the South Dakota Legislature. Each district is represented by 1 senator and 2 representatives. In the Senate, it has been represented by Republican Carl E. Perry since 2025. In the House, it has been represented by Al Novstrup since 2025 and Brandei Schaefbauer since 2023.
The district is located in northeastern South Dakota, in Brown County. The district is based in Aberdeen.
South Dakota legislators are elected to two-year terms, with each permitted to serve a maximum of four consecutive two-year terms. Elections are held every even-numbered year.