Simpson is a village in Johnson County, Illinois, United States.

[3] Simpson is located in eastern Johnson County at 37°28′5″N 88°45′23″W / 37.46806°N 88.75639°W / 37.46806; -88.75639 (37.467977, -88.756277),[4] in the valley of Cedar Creek, a south-flowing tributary of Bay Creek and part of the Ohio River watershed.

Illinois Route 147 passes through the village, leading southwest 9 miles (14 km) to Vienna, the county seat, and east 5 miles (8 km) to its terminus at Glendale.

19.0% of all households were made up of individuals, and 4.8% had someone living alone who was 65 years of age or older.

There were no families and 7.0% of the population living below the poverty line, including no under eighteens and none of those over 64.