The township was established in 1850 by settlers who came from the town of Warren, New York.

Both were named in honor of Major General Joseph Warren, killed at the Battle of Bunker Hill.

Warren Township covers an area of 36.77 square miles (95.2 km2); of this, 0.78 square miles (2.0 km2) or 2.03 percent is water.

The township contains seven cemeteries: Highland Memorial Park, Sant Sava Monastery, Serbian Monastery, Spaulding, Spaulding Corners, Swan Family and Warren.

The racial makeup of the township was 55.8% White, 12.2% Asian, 9.1% Black or African American, 0.9% American Indian or Alaska Native, 0.1% Native Hawaiian or Pacific Islander, 10.8% from other races, and 11.2% from two or more races.