Founded in 1839, Grundy County is one of 114 counties in the state of Missouri. Historically, Grundy County was formed from Livingston County. The city of Trenton is the county seat. With FIPS code of 79, Grundy County has a population of 9,720 and area of 436 square miles (1,129 km2).
List of all cities in Grundy County, MO alphabetically
| City/Town | Postal Code | Area Code |
| Galt, MO | 64641 | 660 |
| Laredo, MO | 64652 | 660 |
| Spickard, MO | 64679 | 660 |
| Trenton, MO | 64683 | 660 |