Towns of Marion County
- Amos - see Fairview
- Barnesville
- Barrackville
- Baxter
- Boothsville
- Briartown - see Monongah
- Buffalo Station - see Barnesville
- Carolina
- Clarkson - see Monongah
- Colfax
- Damascus Mills - see Barnesville
- Camdensburg - see Monongah
- Fairmont (county seat)
- Fairview
- Farmington
- Four States
- Grant Town
- Idamay
- Jordan
- Kingmont
- Koontown - see Mannington
- Mannington
- Metz
- Middletown - see Fairmont
- Monongah
- Montana Mines
- Palatine
- Paw Paw City - see Fairview
- Pleasant Valley
- Rachel
- Rivesville
- Underwood - see Farmington
- West Fairmont
- Willeyville (Willeytown) - see Farmington
- Worthington