| Al Koistinen | |
| State House2: | South Dakota |
| District2: | 6th |
| Term Start2: | 2001 |
| Term End2: | 2008 |
| Birth Date: | 21 March 1948 |
| Party: | Republican |
| Profession: | Businessman |
| Residence: | Watertown, South Dakota |
Alton B. Koistinen (born March 21, 1948) is an American former politician. He was served in the South Dakota House of Representatives from 2001 to 2008.[1] [2]