Millbrook Township is located in Peoria County, Illinois.

As of the 2020 census, its population was 419 and it contained 192 housing units.

[2] As of the 2010 census, its population was 488 and it contained 197 housing units.

[3] According to the 2010 census, the township has a total area of 36.67 square miles (95.0 km2), of which 36.57 square miles (94.7 km2) (or 99.73%) is land and 0.11 square miles (0.28 km2) (or 0.30%) is water.

This Peoria County, Illinois location article is a stub.