Founded in 1821, Montgomery County is one of 102 counties in the state of Illinois. Historically, Montgomery County was formed from Bond and Madison County. The city of Hillsboro is the county seat. With FIPS code of 135, Montgomery County has a population of 28,084 and area of 703 square miles (1,821 km2).
List of all cities in Montgomery County, IL alphabetically
| City/Town | Postal Code | Area Code |
| Atwater, IL | 62572 | 217 |
| Audubon, IL | 62075 | 217 |
| Barnett, IL | 62056 | 217 |
| Butler, IL | 62015 | 217 |
| Chapman, IL | 62032 | 217 |
| Coalton, IL | 62075 | 217 |
| Coffeen, IL | 62017 | 217 |
| Donnellson, IL | 62019 | 217 |
| East Fork, IL | 62017 | 217 |
| Farmersville, IL | 62533 | 217 |
| Fillmore, IL | 62032 | 217 |
| Grisham, IL | 62077 | 217 |
| Harvel, IL | 62538 | 217 |
| Hillsboro, IL | 62049 | 217 |
| Hornsby, IL | 62056 | 217 |
| Irving, IL | 62051 | 217 |
| Kortcamp, IL | 62049 | 217 |
| Litchfield, IL | 62056 | 217 |
| Nokomis, IL | 62075 | 217 |
| Ohlman, IL | 62076 | 217 |
| Panama, IL | 62077 | 217 |
| Raymond, IL | 62560 | 217 |
| Schram City, IL | 62049 | 217 |
| South Fillmore, IL | 62032 | 217 |
| Taylor Springs, IL | 62089 | 217 |
| Van Burensburg, IL | 62032 | 217 |
| Waggoner, IL | 62572 | 217 |
| Walshville, IL | 62091 | 217 |
| Wenonah, IL | 62075 | 217 |
| Witt, IL | 62094 | 217 |