Voter file loaded June 8, 2026 · figures are from that file, held as a fixed record
Suffolk County, New York has 1,083,400 active registered voters — 31.3% Republican, 32.7% Democratic, and 30.2% with no party affiliation, as of June 2026.
Party registration
How Suffolk County voted for president
Election results are public records.
Suffolk County at a glance.
Suffolk County had an estimated 1,535,909 residents in July 2024, the fourth most populous of New York's 62 counties, up 0.7% since the 2020 census. Of those, 1,221,421 are 18 or older, the voting-age population, and 19.0% are 65 or older. Its 1,083,400 active registered voters equal about 88.7% of that voting-age population.
It covers 911 square miles of land (1,686 people per square mile). The largest towns and cities are Brookhaven (492,759), Islip (339,170), Babylon (218,566), Huntington (204,706) and Smithtown (116,228). The American Community Survey (2020-2024) puts it at a median age of 41.7, a median household income of $130,686, 40.2% of adults 25 and older holding a bachelor's degree or higher and 82.2% of occupied homes owned by the people living in them.
In 2024, 759,361 votes were cast for president, about 62.2% of the voting-age population; the Democratic ticket took 45.0% and the Republican ticket 55.0%. The two-party margin moved from D+6.0 in 2008 to R+10.0 in 2024.
- Population (2024 estimate)
- 1,535,909
- Population (2020 census base)
- 1,525,913
- Voting-age population (18+)
- 1,221,421
- Active voters per 100 adults
- 88.7
- Residents 65 and older
- 19.0%
- People per square mile
- 1,686
- Land area
- 911 sq mi
- Median age
- 41.7
- Median household income
- $130,686
- Adults 25+ with a bachelor's degree
- 40.2%
- Owner-occupied homes
- 82.2%
Largest towns and cities
- Brookhaven 492,759
- Islip 339,170
- Babylon 218,566
- Huntington 204,706
- Smithtown 116,228
Presidential vote, 2008–2024
| Year | Democratic | Republican | Margin | Votes cast |
|---|---|---|---|---|
| 2024 | 45.0% | 55.0% | R+10.0 | 759,361 |
| 2020 | 49.4% | 49.4% | even | 771,541 |
| 2016 | 44.3% | 52.5% | R+8.2 | 625,720 |
| 2012 | 50.8% | 48.0% | D+2.8 | 540,653 |
| 2008 | 52.5% | 46.5% | D+6.0 | 659,779 |
Sources: U.S. Census Bureau Vintage 2024 population estimates and 2024 Gazetteer; American Community Survey 2020–2024 5-year estimates; certified county presidential returns. Growth, density and turnout are simple arithmetic on those figures.
Running in Suffolk County?
The voter file is loaded. Create your campaign and start canvassing in minutes.
Start free in Suffolk CountyAlso see: Motion51 in New York · How to run for office in Suffolk County · Pricing