Allendale
- County:
- Bergen County
- County Seat:
- No
- Area (mi²):
- 3.097
- State:
- New Jersey
Allendale is a borough located in Bergen County, New Jersey. Allendale has a 2026 population of 6,928. Allendale is currently growing at a rate of 1.08% annually and its population has increased by 1.45% since the most recent census, which recorded a population of 6,829 in 2020.