Lyndon Township is located in Whiteside County, Illinois. As of the 2010 census, its population was 1,057 and it contained 460 housing units.
Geography
According to the 2010 census, the township has a total area of 28.08 square miles (72.7 km2), of which 27.27 square miles (70.6 km2) (or 97.12%) is land and 0.81 square miles (2.1 km2) (or 2.88%) is water.