Carrollton is a city in Greene County, Illinois, United States. The population was 2,605 at the 2000 census. It is the county seat of Greene County.
Carrollton is located at 39°17′48″N 90°24′29″W / 39.29667°N 90.40806°W / 39.29667; -90.40806 (39.296662, -90.408059).
According to the United States Census Bureau, the city has a total area of 1.7 square miles (4.3 km²), all of it land.