| | Sullivan County | MO | 29211 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=SullivanCounty+MO |
| | Stone County | MO | 29209 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=StoneCounty+Missouri |
| | Stoddard County | MO | 29207 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=StoddardCounty+MO |
| | Shelby County | MO | 29205 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=ShelbyCounty+MO |
| | Shannon County | MO | 29203 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=ShannonCounty+MO |
| | Scott County | MO | 29201 | | Sikeston, MO 43460 | Cape Girardeau-Sikeston,
MO-IL 164 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=ScottCounty+MO |
| | Scotland County | MO | 29199 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=ScotlandCounty+MO |
| | Schuyler County | MO | 29197 | | Kirksville, MO 28860 | | Outlying | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=SchuylerCounty+MO |
| | Saline County | MO | 29195 | | Marshall, MO 32180 | | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=SalineCounty+MO |
| | St. Louis County | MO | 29189 | | St. Louis, MO-IL 41180 | St. Louis-St.
Charles-Farmington, MO-IL 476 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=St.LouisCounty+MO |