Leonia
- County:
- Bergen County
- County Seat:
- No
- Area (mi²):
- 1.523
- State:
- New Jersey
Leonia is a borough located in Bergen County, New Jersey. Leonia has a 2026 population of 9,492. Leonia is currently growing at a rate of 1.12% annually and its population has increased by 2.1% since the most recent census, which recorded a population of 9,297 in 2020.