Ohio State Senate District 12

State Legislative District Profile (Upper Chamber)

Overview

District ID
oh-sd-012
State
Ohio
Chamber
Upper chamber (state senate)
District Code
012
Land Area
2,712.1 sq mi
Water Area
21.2 sq mi

Boundary

Boundary of Ohio State Senate District 12

Boundary as GeoJSON

Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.

Counties

CountyOverlapShare of district landShare of county land
Mercer County462.45 sq mi17.1%100.0%
Champaign County428.99 sq mi15.8%100.0%
Shelby County407.69 sq mi15.0%100.0%
Allen County402.55 sq mi14.8%100.0%
Auglaize County401.39 sq mi14.8%100.0%
Darke County368.03 sq mi13.6%61.5%
Logan County241.03 sq mi8.9%52.6%

Showing all 7 counties

Places

PlaceOverlapShare of district landShare of place land
Lima city13.62 sq mi0.5%100.0%
Sidney city11.97 sq mi0.4%100.0%
Bellefontaine city10.05 sq mi0.4%99.2%
Fort Shawnee CDP9.51 sq mi0.4%100.0%
Urbana city7.91 sq mi0.3%95.1%
Greenville city6.65 sq mi0.2%100.0%
Wapakoneta city6.39 sq mi0.2%95.4%
Maria Stein CDP5.08 sq mi0.2%100.0%
Celina city5.03 sq mi0.2%100.0%
St. Marys city4.67 sq mi0.2%99.9%
Bluffton village2.55 sq mi0.1%68.9%
New Bremen village2.32 sq mi0.1%99.3%
Gomer CDP2.29 sq mi0.1%100.0%
Minster village2.08 sq mi0.1%96.9%
Delphos city1.97 sq mi0.1%59.3%
Versailles village1.95 sq mi0.1%96.9%
Coldwater village1.94 sq mi0.1%100.0%
Westminster CDP1.82 sq mi0.1%100.0%
St. Henry village1.72 sq mi0.1%99.8%
Jackson Center village1.72 sq mi0.1%100.0%
St. Paris village1.62 sq mi0.1%100.0%
East Liberty CDP1.58 sq mi0.1%100.0%
Rosewood CDP1.35 sq mi<0.1%100.0%
Botkins village1.26 sq mi<0.1%99.9%
Fort Recovery village1.24 sq mi<0.1%100.0%

Showing top 25 of 69 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
OH District 4233,33767.8%29.7%62.0%
OH District 542,52812.4%5.4%17.1%
OH District 836,44410.6%4.6%13.6%
OH District 1531,9439.3%4.1%7.4%

Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).

Voters

Registered Voters
225,509
Active Voters
201,760 (89.5%)

Party Registration

PartyVotersShare
Democratic10,0914.5%
Republican67,16129.8%
Unaffiliated00.0%
Other parties00.0%
No party recorded148,25765.7%

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–202654,482 (24.2%)0 (0.0%)5,405 (2.4%)
2023–2024177,716 (78.8%)7,395 (3.3%)49,750 (22.1%)
2021–2022125,864 (55.8%)8,244 (3.7%)53,700 (23.8%)
2019–2020163,606 (72.5%)12,316 (5.5%)38,534 (17.1%)
2017–2018119,148 (52.8%)8,449 (3.7%)37,937 (16.8%)
2015–2016141,877 (62.9%)14,592 (6.5%)66,400 (29.4%)
2013–201482,872 (36.7%)6,894 (3.1%)28,255 (12.5%)
2011–2012124,858 (55.4%)6,600 (2.9%)40,330 (17.9%)

Turnout counts today's registered voters with a counted ballot in the cycle's elections (the odd and even year), as a share of today's registered voters. Voters who have since left the rolls are not counted.

Browse the voter list for this district (premium access; sign-in required)

Source: Civitech voter file snapshot as of 01/20/2026. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".

Demographics

Total Population
343,602 (± 760)
Median Age
40.3
Median Household Income
$71,001 (± $1,262)
High School Graduate or Higher (age 25+)
92.7%
Bachelor's Degree or Higher (age 25+)
20.1%

Population by Age

GroupPeopleShare
Under 1881,86423.8%
18 to 64196,19957.1%
65 and over65,53919.1%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)8,4962.5%
White, not Hispanic305,14288.8%
Black, not Hispanic13,1393.8%
Asian, not Hispanic2,1190.6%
American Indian / Alaska Native, not Hispanic4130.1%
Native Hawaiian / Pacific Islander, not Hispanic450.0%
Some other race, not Hispanic8890.3%
Two or more races, not Hispanic13,3593.9%

Source: U.S. Census Bureau, American Community Survey 2020-2024 ACS 5-year estimates (tables B01001, B01002, B01003, B03002, B15003, B19013) for this state legislative district. Estimates are survey-based; ± figures are 90% margins of error.

Citizen Voting Age Population

Total Citizen Population
340,927
Citizen Voting Age Population (CVAP)
259,219

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic333,11797.7%
Hispanic7,8072.3%
White307,25390.1%
Black12,8543.8%
Asian1,4670.4%
American Indian / Alaska Native4290.1%
Native Hawaiian / Pacific Islander130.0%
Two or More Races1,2780.4%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic254,28598.1%
Hispanic4,9291.9%
White237,09591.5%
Black11,6684.5%
Asian1,9420.7%
American Indian / Alaska Native3,0591.2%
Native Hawaiian / Pacific Islander110.0%
Two or More Races8990.3%

Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).