Warrenton Township was organized in 1879, and named for Charles H. Warren, a railroad official.

[3] According to the United States Census Bureau, the township has a total area of 35.5 square miles (91.8 km2), all land.

As of the census[1] of 2000, there were 93 people, 31 households, and 27 families residing in the township.

The racial makeup of the township was 98.92% White and 1.08% Native American.

12.9% of all households were made up of individuals, and 3.2% had someone living alone who was 65 years of age or older.