Voter file loaded June 8, 2026 · figures are from that file, held as a fixed record
Jefferson County, New York has 62,472 active registered voters — 42.9% Republican, 23.5% Democratic, and 28.2% with no party affiliation, as of June 2026.
Party registration
How Jefferson County voted for president
Election results are public records.
Jefferson County at a glance.
Jefferson County had an estimated 113,140 residents in July 2024, the 25th most populous of New York's 62 counties, down 3.1% since the 2020 census. Of those, 85,830 are 18 or older, the voting-age population, and 16.2% are 65 or older. Its 62,472 active registered voters equal about 72.8% of that voting-age population.
It covers 1,268 square miles of land (89 people per square mile). The largest towns and cities are Le Ray (24,274), Watertown (24,038), Brownville (5,768), Wilna (5,598) and Watertown (5,464). The American Community Survey (2020-2024) puts it at a median age of 33.7, a median household income of $66,301, 26.5% of adults 25 and older holding a bachelor's degree or higher and 54.7% of occupied homes owned by the people living in them.
In 2024, 42,743 votes were cast for president, about 49.8% of the voting-age population; the Democratic ticket took 38.2% and the Republican ticket 61.8%. The two-party margin moved from R+5.3 in 2008 to R+23.6 in 2024.
- Population (2024 estimate)
- 113,140
- Population (2020 census base)
- 116,716
- Voting-age population (18+)
- 85,830
- Active voters per 100 adults
- 72.8
- Residents 65 and older
- 16.2%
- People per square mile
- 89
- Land area
- 1,268 sq mi
- Median age
- 33.7
- Median household income
- $66,301
- Adults 25+ with a bachelor's degree
- 26.5%
- Owner-occupied homes
- 54.7%
Largest towns and cities
- Le Ray 24,274
- Watertown 24,038
- Brownville 5,768
- Wilna 5,598
- Watertown 5,464
Presidential vote, 2008–2024
| Year | Democratic | Republican | Margin | Votes cast |
|---|---|---|---|---|
| 2024 | 38.2% | 61.8% | R+23.6 | 42,743 |
| 2020 | 39.5% | 58.4% | R+18.9 | 43,848 |
| 2016 | 35.9% | 58.2% | R+22.3 | 34,263 |
| 2012 | 47.9% | 50.8% | R+2.9 | 32,051 |
| 2008 | 46.7% | 52.0% | R+5.3 | 38,886 |
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.
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