Seneca County is a county located in the U.S. state of Ohio. As of the most recent data available, the county has a population of approximately 58,683 people, with a population density of about 106.50 persons per square mile.
The county spans a total land area of 551.00 square miles (1,427.00 square kilometers). The administrative center and county seat is Tiffin, which often serves as a hub for local governance and services. The largest city within the county by population is Tiffin.
Geographically, Seneca County experiences varied elevations, with its highest point at Attica 950 ft and its lowest point at Bettsville 707 ft. The region operates in the UTC-5.