Your Guide to Seneca County, Ohio
Looking for trusted businesses, services and local resources in Seneca County, Ohio? FindItOhio.com helps residents and visitors discover local companies, professionals and community information across Seneca County, including Tiffin, the county seat.
Quick answer: Seneca County is one of Ohio’s 88 counties. Its county seat is Tiffin, it was established in 1820, and it has an estimated 54,522 residents as of 2025.
At a Glance
- County seat: Tiffin
- Established: Apr 1, 1820
- Formed from: Huron County
- Named for: Seneca Indians, who had a reservation in the county area at the time
- Estimated population (2025): 54,522
- Total area: 550.59 sq mi
- FIPS code: 39147
About Seneca County
Seneca County is a county located in the northwestern part of the U.S. state of Ohio. As of the 2020 census, the population was 55,069. Its county seat is Tiffin. The county was created in 1820 and organized in 1824. It is named for the Seneca Indians, the westernmost nation of the Iroquois Confederacy. This people were based in present day New York but had territory extending into Pennsylvania and Ohio. Seneca County comprises the Tiffin, OH Micropolitan Statistical Area, which is also included in the Findlay, Tiffin, OH Combined Statistical Area.
History of Seneca County
This area was long occupied by a succession of indigenous peoples. During and after the colonial period, French, British and American fur traders established relations with the historic peoples of the time.
The county was barely inhabited by European Americans until the 1830s, but this period was one of steady migration by settlers from New York and New England. The migration was stimulated by completion of the Erie Canal through New York, which connected the markets by the Great Lakes to the Hudson River and New York City. By 1860 the population of Seneca County had increased to about half the current number of residents. It was developed for agriculture, and grew slowly thereafter. In 1889 900 Luxembourgers settled in Seneca County where they built substantial churches and schools.
Toward the end of the 19th century, during the Great Depression, and the post, World War II baby boom, this area had periods of greater population increase. In 1980 the census recorded a population of 61,901; the total has since declined. Since about 2000, the county’s population declines by about 100 to 300 persons annually, mainly due to a migration deficit of about 300 persons annually. This decline is projected to continue in the future.
Cities and Villages in Seneca County
Cities
Fostoria, Tiffin â€
Villages
Attica, Bettsville, Bloomville, Green Springs, New Riegel, Republic
Find Local Businesses in Seneca County
Browse the FindItOhio.com business directory to find restaurants, contractors, professional services, shops and more serving Seneca County. Own a business here? Add your free business listing so local customers can find you.
Background Checks, Process Serving and Private Investigations
Residents and employers in Seneca County can get BCI and FBI LiveScan fingerprinting, FD-258 fingerprint cards, process serving and licensed private investigations from these Ohio providers:
- Ohio Security & Investigations, Youngstown: licensed private investigations and fingerprinting. Call (888) 341-6960 or visit ohioinvestigators.com.
- 10-8 Protective Services, Columbus: investigations, fingerprinting and process serving. Call (800) 949-8521 or visit 10-8protectiveservices.com.
Frequently Asked Questions
What is the county seat of Seneca County, Ohio?
Tiffin is the county seat of Seneca County, Ohio.
When was Seneca County established?
Seneca County was established on Apr 1, 1820. It was formed from Huron County.
Who or what is Seneca County named for?
Seneca County is named for Seneca Indians, who had a reservation in the county area at the time.
How many people live in Seneca County, Ohio?
Seneca County has an estimated population of 54,522 as of 2025.
What cities are in Seneca County, Ohio?
Cities in Seneca County include Fostoria, Tiffin †.
Where can I find local businesses in Seneca County?
Search the FindItOhio.com business directory to find local businesses and services in Seneca County, Ohio.
How do I list my Seneca County business on FindItOhio.com?
Visit the free business listing page on FindItOhio.com and submit your business name, address, phone number and website.
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County background adapted from the Wikipedia article Seneca County, Ohio, available under the Creative Commons Attribution ShareAlike 4.0 license.