Oldenburg
- County:
- Franklin County
- County Seat:
- No
- Area (mi²):
- 0.43
- State:
- Indiana
Oldenburg is a town located in Franklin County, Indiana. Oldenburg has a 2026 population of 647. Oldenburg is currently declining at a rate of -0.31% annually but its population has increased by 0.78% since the most recent census, which recorded a population of 642 in 2020.
The median household income in Oldenburg is $79,583 with a poverty rate of 18.57%. The median age in Oldenburg is 39.8 years: 36.3 years for males, and 57.9 years for females. For every 100 females there are 70.7 males.