
Marietta
- County:
- Washington County
- County Seat:
- Yes
- Area (mi²):
- 8.429
- State:
- Ohio
Marietta is a city located in Washington County, Ohio. Marietta has a 2025 population of 12,913. It is also the county seat of .Marietta is currently declining at a rate of -0.68% annually and its population has decreased by -3.31% since the most recent census, which recorded a population of 13,355 in 2020.
The average household income in Marietta is $79,856 with a poverty rate of 19%. The median age in Marietta is 39.3 years: 38.5 years for males, and 39.8 years for females.