NPMHU Local 328
- Mail handlers union in Sioux Falls, SD.
- http://www.npmhu.org/NPMHUOffices/Local328.htm

South Dakota State Employees Organization
- Independent organization for South Dakota's state employees. Membership information, current issues, and contact details.
- http://www.sdseo.org

South Dakota Education Association
- Union representing teachers in the state. Affiliated with the National Education Association.
- http://www.sdea.org/

IBEW Local 426
- Chartered as a construction local union in 1916, today IBEW 426 has 574. Local 426 serves eastern South Dakota and four countries in southwestern Minnesota, doing inside electrical construction, outside line construction, residential wiring, telecommuni
- http://www.dakibew.org/Local426.html