Wheat fields on the southern side of State Route 12 just west of County Road 5, just south of Amsden, in Jackson Township, Seneca County, Ohio, United States. – Nyttend, Public domain – Wikimedia Commons Jackson Township is located in Seneca County. About 1,401 people live here (as of 2020). Between 2010 and 2020, the population declined from 1,512 to 1,401. The region is at 221 meters above sea level. There are about 71 streets in Jackson Township. Jackson Township is township in Seneca County, Ohio. Among other things, Jackson Township has schools.