Flagg Township is located in Ogle County, Illinois.

As of the 2010 census, its population was 13,562 and it contained 5,525 housing units.

[2] Flagg Township was named for Richard P. Flagg, a pioneer settler.

[3] According to the 2010 census, the township has a total area of 35.61 square miles (92.2 km2), of which 35.52 square miles (92.0 km2) (or 99.75%) is land and 0.08 square miles (0.21 km2) (or 0.22%) is water.

This Ogle County, Illinois location article is a stub.