Connecticut State Senate District 18

State Legislative District Profile (Upper Chamber)

Overview

District ID
ct-sd-018
State
Connecticut
Chamber
Upper chamber (state senate)
District Code
018
Land Area
298.1 sq mi
Water Area
31.1 sq mi

Boundary

Boundary of Connecticut State Senate District 18

Boundary as GeoJSON

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

Places

PlaceOverlapShare of district landShare of place land
Conning Towers-Nautilus Park CDP5.20 sq mi1.7%100.0%
Old Mystic CDP4.29 sq mi1.4%100.0%
Mystic CDP3.65 sq mi1.2%100.0%
Pawcatuck CDP3.41 sq mi1.1%100.0%
Groton city3.08 sq mi1.0%100.0%
Moosup CDP2.44 sq mi0.8%100.0%
Plainfield Village CDP1.71 sq mi0.6%100.0%
Long Hill CDP1.54 sq mi0.5%47.5%
Noank CDP1.52 sq mi0.5%100.0%
Poquonock Bridge CDP1.34 sq mi0.5%100.0%
Wauregan CDP1.05 sq mi0.4%63.9%
Jewett City borough0.70 sq mi0.2%100.0%
Groton Long Point borough0.43 sq mi0.1%100.0%
Stonington borough0.34 sq mi0.1%100.0%
Mashantucket CDP0.01 sq mi<0.1%0.2%

Showing all 15 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
CT District 299,206100.0%13.8%100.0%

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

Voters

Registered Voters
74,540
Active Voters
69,241 (92.9%)

Party Registration

PartyVotersShare
Democratic21,43028.7%
Republican17,80323.9%
Unaffiliated33,98745.6%
Other parties1,3201.8%
No party recorded00.0%

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–2026158 (0.2%)0 (0.0%)0 (0.0%)
2023–202449,552 (66.5%)0 (0.0%)0 (0.0%)
2021–202237,591 (50.4%)0 (0.0%)0 (0.0%)
2019–202048,358 (64.9%)0 (0.0%)0 (0.0%)
2017–201835,986 (48.3%)0 (0.0%)0 (0.0%)
2015–201638,172 (51.2%)0 (0.0%)0 (0.0%)
2013–201425,716 (34.5%)0 (0.0%)0 (0.0%)
2011–201227,998 (37.6%)0 (0.0%)0 (0.0%)

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 11/04/2025. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".

Demographics

Total Population
99,493 (± 115)
Median Age
43.3
Median Household Income
$90,470 (± $3,042)
High School Graduate or Higher (age 25+)
94.9%
Bachelor's Degree or Higher (age 25+)
36.7%

Population by Age

GroupPeopleShare
Under 1818,05618.1%
18 to 6460,71461.0%
65 and over20,72320.8%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)7,5257.6%
White, not Hispanic79,46979.9%
Black, not Hispanic2,7602.8%
Asian, not Hispanic3,6063.6%
American Indian / Alaska Native, not Hispanic2810.3%
Native Hawaiian / Pacific Islander, not Hispanic450.0%
Some other race, not Hispanic2970.3%
Two or more races, not Hispanic5,5105.5%

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
97,511
Citizen Voting Age Population (CVAP)
79,555

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic90,45392.8%
Hispanic7,0607.2%
White80,38382.4%
Black2,6412.7%
Asian2,9713.0%
American Indian / Alaska Native3060.3%
Native Hawaiian / Pacific Islander480.0%
Two or More Races6370.7%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic75,36694.7%
Hispanic4,1885.3%
White68,05085.5%
Black2,8963.6%
Asian3,0123.8%
American Indian / Alaska Native1,1441.4%
Native Hawaiian / Pacific Islander480.1%
Two or More Races3880.5%

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