| Mark Johnston | |
| State Senate2: | South Dakota |
| District2: | 12th |
| Term Start2: | 2011 |
| Term End2: | May 31, 2013 |
| Predecessor2: | Sandy Jerstad |
| Successor2: | Blake Curd |
| Birth Date: | 21 September 1962 |
| Birth Place: | Sioux City, Iowa, U.S. |
| Party: | Republican |
| Spouse: | Julie |
| Residence: | Sioux Falls, South Dakota |
| Children: | 2 |
John Mark Johnston (born September 21, 1962) is an American former politician. He served in the South Dakota Senate from 2011 to 2013.[1] [2]