Jefferson Township covers an area of 36.1 square miles (93 km2); 0.35 square miles (0.91 km2) (0.97 percent) of this is water. Lake Cicott is in this township.
The township contains two cemeteries: Davis and Zion. Davis Cemetery is located a mile east of Burnettsville and a half mile east of the White County-Cass county line, and is commonly referred to as the Davis Cemetery Burnettsville in obituaries. It was also known as the Winegardner Cemetery.