Seneca Township, McHenry County, Illinois

Seneca Township is located in McHenry County, Illinois. As of the 2020 census, its population was 2,893 and it contained 1,102 housing units.

Geography
According to the 2010 census, the township has a total area of 35.96 sqmi, of which 35.95 sqmi (or 99.97%) is land and 0.01 sqmi (or 0.03%) is water.