County · Ohio

Seneca County, Ohio

Seneca County, Ohio. Seneca County had 54,522 residents in 2025 by the Census Bureau's estimate, down 1.0% since 2020, while Ohio grew 0.9%. It holds 30 places (8 cities, villages and boroughs, 15 towns and townships and 7 census-designated) and 14 census tracts. GEOID 39147.

Seneca County is the county of the Tiffin, OH micropolitan statistical area (the Census Bureau's July 2023 delineation).

Residents, July 2025 estimate

54,522

Census Bureau estimate (no margin published)
2020 Census count: 55,069 · ACS 2020-2024: 54,770

Median household income

$66,025

±$3,286 (90% margin)
Ohio: $71,389

Median home value

$154,700

±$3,665 (90% margin)
Ohio: $214,800

Median gross rent

$856

±$20 (90% margin)
Ohio: $1,034

How many people live in Seneca County, and is it growing?

The 2020 Census counted 55,069 residents in Seneca County. The Census Bureau estimates 54,522 for July 1, 2025, down 1.0% since 2020, while Ohio grew 0.9%. The 2020-2024 American Community Survey puts the population at 54,770 over 551 square miles of land.

July 2020→2021 −86 (54,975)
2021→2022 −325 (54,650)
2022→2023 +69 (54,719)
2023→2024 −25 (54,694)
2024→2025 −172 (54,522)

Seneca County in Ohio. Boundaries: Census Bureau 2024.

Counts, ACS 2020-2024 5-year estimates, with the change from 2015-2019
Measure	Seneca County	Ohio	Change since 2015-2019
Total population	54,770	11,810,293	−581
Households	22,279±341	4,863,191	+631
Average household size	2.34±0.03	2.37	−0.07
Housing units	23,982±111	5,292,391	no clear change

Seneca County's population since 2000

From 58,683 in 2000 to 54,522 in 2025: down 7.1%. The 2000, 2010 and 2020 figures are census counts. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.

2000 Census 58,683
2005 (estimate) 57,664
2010 Census 56,745
2015 (estimate) 55,672
2020 Census 55,069
2025 (estimate) 54,522

Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); PEP Vintage 2025 (CO-EST2025); 2020 Census · Check it at data.census.gov

What cities and towns are in Seneca County?

Seneca County holds 30 places: 8 cities, villages and boroughs (incorporated places), 15 towns and townships (county subdivisions with their own government) and 7 census-designated places. The largest is Tiffin with 17,803 residents (2025 estimate). Places that cross a county line are listed with the share of their 2020 residents who live in this county.

Places in Seneca County, ACS 2020-2024 5-year estimates. Ring: estimate with a coefficient of variation over 40%.

Tiffin	city	17,953	17,818±31	$56,198	$142,200	14.8%	100%
Fostoria	city	13,046	12,344±394	$54,151	$87,200	16.4%	69%
Clinton Township, Seneca County	township	4,105	4,040±41	$93,355	$210,500	8.8%	100%
Hopewell Township, Seneca County	township	2,672	2,703±28	$61,434	$205,100	9.6%	100%
Loudon Township, Seneca County	township	2,246	2,613±458	$83,185	$210,400	8.3%	100%
Eden Township, Seneca County	township	2,042	1,702±331	$113,500	$223,600	4.3%	100%
Liberty Township, Seneca County	township	2,029	1,937±304	$64,093	$120,600	12.3%	100%
Venice Township	township	1,683	1,830±387	$86,442	$151,300	6.7%	100%
Big Spring Township	township	1,683	1,756±348	$73,688	$181,000	5.8%	100%
Scipio Township, Seneca County	township	1,674	1,700±396	$52,500	$160,800	21.1%	100%
Bloom Township, Seneca County	township	1,624	1,408±268	$78,226	$122,800	14.6%	100%
Pleasant Township, Seneca CountyGEOID 3914763394	township	1,477	1,137±249	$77,396	$193,900	4.1%	100%
Seneca Township, Seneca County	township	1,444	1,278±239	$91,892	$198,500	3.1%	100%
Jackson Township, Seneca County	township	1,401	1,517±428	$106,875	$165,500	12.6%	100%
Thompson Township, Seneca County	township	1,370	1,535±333	$80,313	$169,700	9.1%	100%
Adams Township, Seneca CountyGEOID 3914700324	township	1,247	1,403±348	$106,607	$216,400	4.0%	100%
Attica	village	873	755±182	$69,063	$113,800	10.2%	100%
Bloomville	village	867	721±176	$69,000	$96,800	17.0%	100%
Reed TownshipGEOID 3914765942	township	738	745±228	$111,411	$176,300	13.6%	100%
Green Springs	village	1,233	1,170±264	$69,531	$83,100	8.7%	52%
Bettsville	village	595	562±157	$65,417	$99,900	14.7%	100%
Republic	village	556	456±113	$63,125	$85,000	10.3%	100%
BascomGEOID 3904094	CDP	397	298±176	$90,592	$145,500	0.0%	100%
New Riegel	village	286	316±113	$63,750	$119,000	15.2%	100%
Fort SenecaGEOID 3927930	CDP	230	113±71	$39,375	$204,700	0.0%	100%
Flat RockGEOID 3927356	CDP	227	340±195	not published	$92,500	24.7%	100%
KansasGEOID 3939578	CDP	175	200±215	$53,144	$73,800	40.0%	100%
MelmoreGEOID 3948972	CDP	173	112±80	$69,018	not published	8.9%	100%
McCutchenvilleGEOID 3945892	CDP	371	346±207	$83,393	$154,200	0.0%	39%
Old FortGEOID 3958156	CDP	143	81±72	not published	not published	0.0%	100%

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 place-by-county parts · Check it at data.census.gov

Who lives in Seneca County?

The median resident of Seneca County is 40.2 years old; 21.4% are under 18 and 19.2% are 65 or older. The largest group is non-Hispanic white residents at 87.8%, then Hispanic or Latino residents (of any race) at 5.7%. 1.2% of residents were born outside the United States.

Age, origin and education, ACS 2020-2024 5-year estimates. Race groups are non-Hispanic; Hispanic includes any race.
Measure	Seneca County	Ohio	Change since 2015-2019
Median age	40.2±0.4	39.7	no clear change
Under 18 years	21.4%±0.1 pts	22.0%	–
65 years and over	19.2%±0.2 pts	18.3%	–
Hispanic or Latino (any race)	5.7%	4.8%	+0.6 pts
White alone, not Hispanic	87.8%±0.3 pts	75.8%	−2.0 pts
Black or African American alone, not Hispanic	2.4%±0.4 pts	12.0%	no clear change
Asian alone, not Hispanic	0.5%±0.2 pts	2.5%	no clear change
American Indian and Alaska Native alone, not Hispanic	0.2%±0.1 pts	0.1%	–
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0.0%±0.1 pts	0.0%	–
Two or more races, not Hispanic	3.0%±0.5 pts	4.3%	–
Some other race alone, not Hispanic	0.4%±0.2 pts	0.4%	–
Born outside the United States	1.2%±0.3 pts	5.2%	−0.7 pts
Speak a language other than English at home (age 5+)	2.6%±0.5 pts	8.0%	–
Civilian veterans (age 18+)	6.8%±0.7 pts	6.6%	–
With a disability	15.2%±1.0 pts	14.4%	–
No health insurance coverage	5.3%±0.8 pts	6.4%	no clear change
High school graduate or higher (age 25+)	93.3%±0.8 pts	91.8%	–
Bachelor's degree or higher (age 25+)	20.6%±1.7 pts	31.5%	+3.8 pts
Graduate or professional degree (age 25+)	7.6%±1.0 pts	12.2%	–
Moved from another state in the past year	1.0%±0.3 pts	1.6%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov

What do households in Seneca County earn?

Half of Seneca County's 22,279 households earn less than $66,025 a year (±$3,286), against $71,389 in Ohio. In 2015-2019 it was $64,611 in 2024 dollars; the margins of error cannot tell the two periods apart. 11.9% of residents live below the poverty line.

Income and poverty in 2024 dollars, ACS 2020-2024 5-year estimates
Measure	Seneca County	Ohio	Change since 2015-2019
Median household income	$66,025±$3,286	$71,389	no clear change
Mean household income	$82,475±$3,291	$96,990	–
Per capita income	$33,984±$1,330	$40,552	no clear change
People below the poverty line	11.9%±1.2 pts	13.3%	no clear change
Children under 18 below the poverty line	14.7%±2.8 pts	17.8%	no clear change
Households receiving SNAP	13.5%±1.5 pts	12.5%	–
Households with a broadband subscription	88.1%±1.3 pts	90.1%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What does housing cost in Seneca County?

Owners occupy 73.4% of Seneca County's occupied homes and renters 26.6%. The median owner-occupied home is valued at $154,700 by its owner (±$3,665). The median renter pays $856 a month including utilities, and 33.7% of renters pay 35% or more of their income on rent.

Housing, ACS 2020-2024 5-year estimates
Measure	Seneca County	Ohio	Change since 2015-2019
Median home value (owner-occupied)	$154,700±$3,665	$214,800	+$23,631
Median gross rent	$856±$20	$1,034	no clear change
Renters paying 35% or more of income on rent	33.7%±5.1 pts	37.3%	no clear change
Median monthly owner costs, with a mortgage	$1,206±$29	$1,517	–
Owner-occupied homes	73.4%±1.9 pts	67.2%	no clear change
Housing units	23,982±111	5,292,391	no clear change
Homeowner vacancy rate	1.0%±0.7 pts	0.8%	–
Rental vacancy rate	5.8%±2.7 pts	4.4%	–
Single-family detached homes	78.7%±1.7 pts	68.8%	–
Mobile homes	4.2%±0.9 pts	3.4%	–
Built 2020 or later	0.4%±0.2 pts	1.1%	–
Built 1939 or earlier	35.2%±2.0 pts	19.0%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov

How many new homes is Seneca County building?

Builders took permits for 81 new housing units across Seneca County in 2025 (51 single-family), 1.5 per 1,000 residents.

2019 83 units
2020 26 units
2021 48 units
2022 45 units
2023 39 units
2024 43 units
2025 81 units

Source: Building Permits Survey, annual county files 2019-2025, U.S. Census Bureau · Census Building Permits Survey

How do people in Seneca County get to work?

81.6% of Seneca County's workers drive alone and 5.9% work from home. The average trip to work takes 20.7 minutes. The unemployment rate in 2020-2024 averaged 3.6%.

Work and commuting, ACS 2020-2024 5-year estimates
Measure	Seneca County	Ohio	Change since 2015-2019
In the labor force (age 16+)	61.5%±1.3 pts	63.1%	–
Unemployment rate	3.6%±0.8 pts	4.8%	no clear change
Drove alone to work	81.6%±1.7 pts	75.1%	–
Carpooled	7.4%±1.2 pts	7.5%	–
Public transportation	0.2%±0.2 pts	1.0%	–
Walked	4.0%±1.1 pts	2.0%	–
Worked from home	5.9%±1.1 pts	13.0%	+3.8 pts
Mean travel time to work	20.7 min±0.7	23.4 min	−1.2 min

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What are Seneca County's census tracts?

Seneca County is divided into 14 census tracts. Among those with a reliable estimate, median household income runs from $41,391 (Tract 9632) to $86,585 (Tract 9638).

Census tracts of Seneca County, ACS 2020-2024 5-year estimates; sort by any column

Tract 962539147962500	Republic (10%)	3,724	3,713±435	$72,813	$167,600	$961	15.7%
Tract 962639147962600	Old Fort (7%)	3,867	3,609±420	$83,144	$187,200	$833	4.3%
Tract 962739147962700	Bettsville (11%)	3,439	3,576±428	$75,844	$139,700	$814	11.2%
Tract 962839147962800	Fostoria (75%)	3,444	3,368±329	$57,287	$85,700	$697	11.3%
Tract 962939147962900	Fostoria	3,890	4,208±342	$56,333	$77,900	$872	16.4%
Tract 963039147963000	Fostoria (55%)	3,214	3,349±407	$54,623	$151,100	$681	16.7%
Tract 963139147963100	Bascom (5%)	4,378	4,200±387	$82,754	$198,000	$820	4.0%
Tract 963239147963200	Tiffin (42%)	4,187	3,821±375	$41,391	$116,900	$908	18.8%
Tract 963339147963300	Tiffin (63%)	4,055	3,783±343	$61,603	$132,800	$924	13.2%
Tract 963439147963400	Tiffin (52%)	4,253	4,315±363	$61,333	$152,400	$849	12.6%
Tract 963539147963500	Tiffin	3,638	4,121±403	$51,786	$115,500	$881	18.5%
Tract 963639147963600	Tiffin (78%)	4,206	4,095±415	$76,849	$194,000	$966	7.7%
Tract 963739147963700	Tiffin (39%)	4,949	4,779±423	$77,648	$238,400	$845	9.4%
Tract 963839147963800	Bloomville (14%)	3,825	3,833±356	$86,585	$152,200	$689	8.8%

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Check it at data.census.gov

How does Seneca County compare with Ohio's other counties?

Seneca County's rank among Ohio's counties with a reliable estimate (1 = highest)
Measure	Rank
Population	47th of 88
Growth 2020-2025	62nd of 88
Residents per square mile	55th of 88
Median household income	48th of 88
Median home value	71st of 88
Median gross rent	46th of 88
Poverty rate	53rd of 88
Bachelor's degree or higher	39th of 88
Median age	63rd of 88

Every county in Ohio

Source: PlainCities ranks from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections

Not on this page: crime, weather and schools for Seneca County are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.