Seneca County Extension Office - Branch office of Ohio State University, it combines the needs of local citizens and communities, with new research and technical information. The Political Graveyard: Seneca County, Ohio - Site contains information on the political history of Seneca County, cemeteries and memorial sites in the county. Seneca County Fair - Includes schedule and information about the fair and other events held on the fairgrounds in Tiffin. Seneca County Department of Job And Family Services - Provides services and seminars to assist employers and prospective job seekers. County Map - Map of Seneca County. Seneca County Sheriff's Office - Provides profile of department, law enforcement programs, crime statistics and history. Capitolimpact: Profile for Seneca County - Information on the political infrastructure of the county.