Waldo
- County:
- Marion County
- County Seat:
- No
- Area (mi²):
- 0.648
- State:
- Ohio
Waldo is a village located in Marion County, Ohio. Waldo has a 2026 population of 317. Waldo is currently declining at a rate of -0.31% annually and its population has decreased by -1.86% since the most recent census, which recorded a population of 323 in 2020.
The median household income in Waldo is $64,519 with a poverty rate of 2.16%. The median age in Waldo is 34.6 years: 38.5 years for males, and 33.2 years for females. For every 100 females there are 143.4 males.