
Iselin
- County:
- Middlesex County
- County Seat:
- No
- Area (mi²):
- 3.152
- State:
- New Jersey
Iselin is a CDP located in Middlesex County, New Jersey. Iselin has a 2025 population of 18,465. Iselin is currently declining at a rate of -0.08% annually but its population has increased by 6.39% since the most recent census, which recorded a population of 17,356 in 2020.
The average household income in Iselin is $138,553 with a poverty rate of 6.39%. The median age in Iselin is 38.4 years: 38 years for males, and 39 years for females.