Sullivan County, New York

Sullivan County at a glance.

Sullivan County had an estimated 80,450 residents in July 2024, the 33rd most populous of New York's 62 counties, up 2.3% since the 2020 census. Of those, 63,227 are 18 or older, the voting-age population, and 20.0% are 65 or older. Its 51,384 active registered voters equal about 81.3% of that voting-age population.

It covers 968 square miles of land (83 people per square mile). The largest towns and cities are Thompson (16,736), Fallsburg (15,019), Mamakating (12,721), Liberty (10,385) and Bethel (4,210). The American Community Survey (2020-2024) puts it at a median age of 41.7, a median household income of $72,382, 30.1% of adults 25 and older holding a bachelor's degree or higher and 67.4% of occupied homes owned by the people living in them.

In 2024, 34,935 votes were cast for president, about 55.3% of the voting-age population; the Democratic ticket took 41.6% and the Republican ticket 58.4%. The two-party margin moved from D+9.4 in 2008 to R+16.8 in 2024.

Population (2024 estimate)

80,450

Population (2020 census base)

78,619

Voting-age population (18+)

63,227

Active voters per 100 adults

81.3

Residents 65 and older

20.0%

People per square mile

83

Land area

968 sq mi

Median age

41.7

Median household income

$72,382

Adults 25+ with a bachelor's degree

30.1%

Owner-occupied homes

67.4%

Largest towns and cities

1. Thompson 16,736
2. Fallsburg 15,019
3. Mamakating 12,721
4. Liberty 10,385
5. Bethel 4,210

Presidential vote, 2008–2024

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.