Duncan Township is located in Mercer County, Illinois.

As of the 2010 census, its population was 272 and it contained 124 housing units.

[2] Duncan Township bears the name of Buford Duncan, a pioneer settler.

[3] According to the 2010 census, the township has a total area of 36.66 square miles (94.9 km2), all land.

This Mercer County, Illinois location article is a stub.