Oil & Gas Companies in Washington County, OH
| Company Name | Company Location | Company Type | Most Recent Production |
| 1 | H & S Drilling Co Inc | Frazeysburg, OH 43822 | Oil & Gas Operator | Dec 2016 |
| 2 | H. C. Oil Co. | Weatherford, TX 76085 | Oil & Gas Operator | Nov 2025 |
| 3 | Haddad & Brooks Inc | Washington, PA 15301 | Oil & Gas Operator | Dec 2018 |
| 4 | Haessly Hardwood Lumber Inc | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 5 | Hall Thomas E | Marietta, OH 45750 | Oil & Gas Operator | Dec 2021 |
| 6 | Hamilton Leonard O | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 7 | Harrison Energy | Tippecanoe, OH 44699 | Oil & Gas Operator | Dec 2000 |
| 8 | Headington Oil Company, L.P. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2008 |
| 9 | Hearn Oil Co. LLC | Newport, OH 45768 | Oil & Gas Operator | Dec 2023 |
| 10 | Heinrich Enterprises Inc Dba Washington Operations | Reno, OH 45773 | Oil & Gas Operator | Dec 2024 |
| 11 | High Plains Gas Systems, Inc. | Houston, TX 77019 | Oil & Gas Operator | Nov 2025 |
| 12 | Hopewell Oil & Gas Development Company | Columbus, OH 43228 | Oil & Gas Operator | Dec 2019 |
| 13 | Houghton Investments LLC | Columbus, OH 43235 | Oil & Gas Operator | Dec 2024 |
| 14 | Huffman-Bowers Inc | New Lexington, OH 43764 | Oil & Gas Operator | Dec 2024 |
Production numbers shown above are only for Washington County, OH and for the production period listed.