Dieterich is a village in Effingham County, Illinois, United States.

Dieterich is part of the Effingham, IL Micropolitan Statistical Area.

[4] Dieterich is located in eastern Effingham County and Illinois Route 33 passes through the village, leading northwest 10 miles (16 km) to Effingham and southeast 13 miles (21 km) to Newton.

According to the 2021 census gazetteer files, Dieterich has a total area of 1.37 square miles (3.55 km2), all land.

33.85% of all households were made up of individuals, and 10.15% had someone living alone who was 65 years of age or older.