New York Assembly District 21

State Legislative District Profile (Lower Chamber)

Overview

District ID
ny-hd-021
State
New York
Chamber
Lower chamber
District Code
021
Land Area
15.9 sq mi
Water Area
0.93 sq mi

Boundary

Boundary of New York Assembly District 21

Boundary as GeoJSON

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

Counties

CountyOverlapShare of district landShare of county land
Nassau County15.89 sq mi100.0%5.6%

Showing all 1 county

Places

PlaceOverlapShare of district landShare of place land
Baldwin CDP3.71 sq mi23.3%90.1%
Rockville Centre village3.25 sq mi20.5%100.0%
Freeport village2.39 sq mi15.0%49.3%
Lynbrook village2.01 sq mi12.7%100.0%
Malverne village1.06 sq mi6.7%100.0%
Valley Stream village0.84 sq mi5.3%24.1%
East Rockaway village0.65 sq mi4.1%64.0%
South Hempstead CDP0.56 sq mi3.5%96.8%
Oceanside CDP0.48 sq mi3.0%9.8%
Hewlett CDP0.37 sq mi2.3%42.1%
Hempstead village0.16 sq mi1.0%4.4%
West Hempstead CDP0.16 sq mi1.0%6.0%
Malverne Park Oaks CDP0.13 sq mi0.8%100.0%
North Lynbrook CDP0.09 sq mi0.5%99.5%

Showing all 14 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
NY District 4139,714100.0%18.0%100.0%

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

Voters

Registered Voters
109,049
Active Voters
102,781 (94.3%)

Party Registration

PartyVotersShare
Democratic44,77541.1%
Republican30,95628.4%
Unaffiliated00.0%
Other parties4,3114.0%
No party recorded29,00726.6%

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–202632,399 (29.7%)18 (0.0%)<10 (—)
2023–202473,470 (67.4%)4,879 (4.5%)1,329 (1.2%)
2021–202253,216 (48.8%)7,556 (6.9%)4,983 (4.6%)
2019–202070,505 (64.7%)9,954 (9.1%)2,732 (2.5%)
2017–201851,598 (47.3%)9,586 (8.8%)284 (0.3%)
2015–201658,121 (53.3%)12,187 (11.2%)9,993 (9.2%)
2013–201431,057 (28.5%)4,252 (3.9%)2,180 (2.0%)
2011–201246,155 (42.3%)508 (0.5%)2,591 (2.4%)

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 01/05/2026. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".

Demographics

Total Population
139,409 (± 3,087)
Median Age
41.8
Median Household Income
$140,950 (± $3,703)
High School Graduate or Higher (age 25+)
92.9%
Bachelor's Degree or Higher (age 25+)
47.3%

Population by Age

GroupPeopleShare
Under 1830,13721.6%
18 to 6484,28260.5%
65 and over24,99017.9%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)31,85722.9%
White, not Hispanic66,25847.5%
Black, not Hispanic27,66219.8%
Asian, not Hispanic8,0625.8%
American Indian / Alaska Native, not Hispanic760.1%
Native Hawaiian / Pacific Islander, not Hispanic00.0%
Some other race, not Hispanic1,2220.9%
Two or more races, not Hispanic4,2723.1%

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
131,112
Citizen Voting Age Population (CVAP)
101,523

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic104,46079.7%
Hispanic26,65420.3%
White66,70450.9%
Black27,22220.8%
Asian7,1065.4%
American Indian / Alaska Native760.1%
Native Hawaiian / Pacific Islander900.1%
Two or More Races8180.6%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic83,36082.1%
Hispanic18,16317.9%
White54,99454.2%
Black21,44821.1%
Asian6,1326.0%
American Indian / Alaska Native5090.5%
Native Hawaiian / Pacific Islander280.0%
Two or More Races3940.4%

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