
Marlboro
- County:
- Ulster County
- County Seat:
- No
- Area (mi²):
- 4.985
- State:
- New York
Marlboro is a CDP located in Ulster County, New York. Marlboro has a 2025 population of 3,626. Marlboro is currently declining at a rate of -0.08% annually and its population has decreased by -2.53% since the most recent census, which recorded a population of 3,720 in 2020.
The average household income in Marlboro is $169,603 with a poverty rate of 3.1%. The median age in Marlboro is 44.1 years: 42.1 years for males, and 46.4 years for females.