Oil & Gas Companies in Fairfield County, OH
| Company Name | Company Location | Company Type | Most Recent Production |
| 1 | C T R Resources Inc | Alliance, OH 44601 | Oil & Gas Operator | Dec 2013 |
| 2 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Aug 2025 |
| 3 | Carter Oil And Gas Inc | Richmond, VA 23219 | Oil & Gas Operator | Dec 2011 |
| 4 | Cgas Exploration | Charleston, WV 25301 | Oil & Gas Operator | Dec 2006 |
| 5 | Chesapeake Appalachia, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Sep 2025 |
| 6 | Clymar, Inc | New Lexington, OH 43764 | Oil & Gas Operator | Dec 1996 |
| 7 | Columbus Oilfield Exploration Company | Columbus, OH 43220 | Oil & Gas Operator | Dec 2013 |
| 8 | Comgas Inc | Hebron, OH 43025-9716 | Oil & Gas Operator | Dec 1988 |
| 9 | Cosper Well/H Cosper | Logan, OH 43138 | Oil & Gas Operator | Dec 1996 |
Production numbers shown above are only for Fairfield County, OH and for the production period listed.