| State Senate: | South Dakota |
| District: | 2nd |
| Term Start: | 1989 |
| Term End: | 1996 |
| State House2: | South Dakota |
| District2: | 2nd |
| Term2: | 1975 - 1986 |
| Birth Name: | Ralph Lars Herseth |
| Birth Date: | 16 June 1946 |
| Birth Place: | Aberdeen, South Dakota |
| Party: | Democratic |
| Spouse: | Joyce Styles |
| Profession: | Rancher |
| Residence: | Houghton, South Dakota |
| Children: | 2, including Stephanie |
| Relations: | Ralph Herseth (father) Lorna Herseth (mother) |
| Alma Mater: | University of South Dakota |
Ralph Lars Herseth (born June 16, 1946) is an American former politician. He served in the South Dakota House of Representatives from 1979 to 1986 and in the Senate from 1989 to 1996.[1] [2] He was the son of Ralph and Lorna Herseth.[3]