- Location: Jefferson County, Missouri
- Legal status: Fourth-class city
- Population: 1,675 (Change since 1990: +3.1%)
- Previously known as: Monticello
- Located on MO 21 west of Festus and north of De Soto
- Latitude: 38°13'56" N (+38.2322)
- Longitude: 90°33'46" W (-90.5628)
- Elevation: 802 feet above sea level
- Civil township: Central
- Land area: 2.4 square miles
As the crow flies, Hillsboro is...
| Year | Population | Percent change |
|---|
| 1900 | 254 | -- |
| 1910 | 261 | +2.8% |
| 1920 | 205 | -21.5% |
| 1930 | 233 | +13.7% |
| 1940 | 256 | +9.9% |
| 1950 | 390 | +52.3% |
| 1960 | 457 | +17.2% |
| 1970 | 831 | +81.8% |
| 1980 | 1,508 | +81.5% |
| 1990 | 1,625 | +7.8% |
| 2000 | 1,675 | +3.1% |