| 4401 | Oklahoma Oil Company | Dallas, TX 75206 | Oil & Gas Operator | Aug 2013 |
| 4402 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 4403 | Oklahoma Petroleum Allies LLC | Ardmore, OK 73401 | Oil Operator | Oct 2023 |
| 4404 | Oklahoma Petroleum MGMT Corp | Tulsa, OK 74119 | Oil & Gas Operator | Jun 1993 |
| 4405 | Oklahoma Prime Energy LLC | Ardmore, OK 73401 | Oil Operator | May 2020 |
| 4406 | Oklahoma Prod & Exp Co | Broken Arrow, OK 74012 | Oil & Gas Operator | May 2013 |
| 4407 | Oklahoma Rig & Salvage, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 4408 | Oklahoma SWD Systems Inc | Odessa, TX 79762-8132 | Oil & Gas Operator | Jan 2025 |
| 4409 | Oklahoma Tank Service Inc | Oklahoma City, OK 73143 | Oil Operator | Aug 1997 |
| 4410 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Feb 2025 |
| 4411 | Oklaoleum Oil And Gas Inc | Bristow, OK 74010-0057 | Oil Operator | Jan 2016 |
| 4412 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 4413 | Okt Petroleum Company Inc | Oklahoma City, OK 73118-7425 | Oil & Gas Operator | Oct 2013 |
| 4414 | Oktex Operating LLC | Edmond, OK 73013-1961 | Oil & Gas Operator | May 2020 |
| 4415 | Oky Investments, Inc. | Edmond, OK 73013 | Oil & Gas Operator | Sep 2021 |
| 4416 | Old Dominion Oil Corporation | Oklahoma City, OK 73107 | Oil & Gas Operator | Apr 2009 |
| 4417 | Ole Crow Operating | Wichita Falls, TX 76308 | Oil Operator | Jan 2025 |
| 4418 | Oleum Incorporated | | Oil & Gas Operator | Mar 1996 |
| 4419 | Olia Oil & Gas Services LLC | Cedar Park, TX 78630-2049 | Oil & Gas Operator | Aug 2022 |
| 4420 | Oliphant Gertrud | Holdenville, OK 74848-0849 | Oil Operator | Aug 2013 |
| 4421 | Oliphant Operating LTD LLC | Tulsa, OK 74159-4529 | Oil Operator | Jan 2025 |
| 4422 | Olive Oil & Gas Inc | Jennings, OK 74038 | Oil & Gas Operator | Nov 2024 |
| 4423 | Olympia Oil Inc | Edmond, OK 73083-7088 | Oil & Gas Operator | Jul 2020 |
| 4424 | Olympic Petroleum Company | Tulsa, OK 74114 | Oil & Gas Operator | Jun 1998 |
| 4425 | Omega Energy, LLC | Corpus Chrsti, TX 78418 | Oil & Gas Operator | Apr 2025 |
| 4426 | Omimex International Corporation | Fort Worth, TX 76103-2300 | Oil & Gas Operator | Jan 2025 |
| 4427 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 4428 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 4429 | On-Line Oil Inc | Oklahoma City, OK 73105-5208 | Oil & Gas Operator | Mar 2015 |
| 4430 | Onapa Gas Company LLC | Tulsa, OK 74136-7253 | Gas Operator | Nov 2019 |
| 4431 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 4432 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 4433 | Oneok Gas Processing LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 4434 | Oneok Gas Transportation Co | Tulsa, OK 74121-2089 | Oil & Gas Operator | Oct 2014 |
| 4435 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 4436 | Onpoint Oil & Gas LLC | Oklahoma City, OK 73170-4848 | Oil & Gas Operator | Jan 2025 |
| 4437 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | Feb 2025 |
| 4438 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 4439 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 4440 | Opal Operating Company LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Apr 2025 |
| 4441 | Open Door Holdings Inc | Surprise, AZ 85387-2015 | Oil & Gas Operator | Feb 2024 |
| 4442 | Open Door Productions Inc | Muskogee, OK 74401-1032 | Oil & Gas Operator | Apr 2020 |
| 4443 | Open Range Energy LLC | Jones, OK 73049-8744 | Oil & Gas Operator | Nov 2024 |
| 4444 | Optima Exploration LLC | Tulsa, OK 74116-5664 | Oil & Gas Operator | Mar 2015 |
| 4445 | Opubco Resources Of TX Inc | Dallas, TX 75231 | Oil & Gas Operator | Sep 2005 |
| 4446 | Oracle Resources Oklahoma LP | Dallas, TX 75240-5751 | Oil & Gas Operator | Feb 2008 |
| 4447 | Orason Resources Inc | Tulsa, OK 74169-1225 | Oil & Gas Operator | Nov 2006 |
| 4448 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2025 |
| 4449 | Oren Stone | Erick, OK 73645-4542 | Gas Operator | Jun 2022 |
| 4450 | Orion Exploration LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Apr 2015 |
| 4451 | Orion Exploration Partners LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Jan 2025 |
| 4452 | Orloski John C | Bartlesville, OK 74006 | Oil & Gas Operator | Jan 2025 |
| 4453 | Oryx Crude Trading & Transporation LP | Dallas, TX 75221 | Oil & Gas Operator | Jun 1999 |
| 4454 | Osa Oil & Gas LLC | Tulsa, OK 74131 | Oil & Gas Operator | Aug 2023 |
| 4455 | Osage Energy LLC | Colony, KS 66015 | Oil Operator | Nov 2023 |
| 4456 | Osage Energy Resources LLC | Bartlesville, OK 74005-2527 | Oil & Gas Operator | Jan 2025 |
| 4457 | Osage Exploration & Development Inc | San Diego, CA 92131-3807 | Oil & Gas Operator | Oct 2016 |
| 4458 | Osage Oil & Transportation Inc | Cleveland, OK 74020 | Oil & Gas Operator | Nov 2000 |
| 4459 | Osage Operating | Virginia Beach, VA 23452 | Oil & Gas Operator | Oct 2003 |
| 4460 | Osage Petroleum Corporation | Saint Louis, MO 63131-4691 | Oil & Gas Operator | Mar 2009 |
| 4461 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Feb 2025 |
| 4462 | Osburn Gerald Dba Ozzy & Son Oil & Gas | Drumright, OK 74030-5467 | Oil Operator | Oct 2020 |
| 4463 | Oscar'S Well Service Inc | Okemah, OK 74859 | Oil & Gas Operator | Apr 1998 |
| 4464 | Oshtah Oil Company LLC | Stratford, OK 74872 | Oil & Gas Operator | Sep 2018 |
| 4465 | Oso Resources LLC | Oklahoma City, OK 73118-5022 | Oil & Gas Operator | Jan 2025 |
| 4466 | Osterhout Phillip L | Drumright, OK 74030-0693 | Oil & Gas Operator | Jan 2014 |
| 4467 | Oswego Arbuckle Enterprise Inc | S Coffeyville, OK 74072-9702 | Oil & Gas Operator | Mar 2015 |
| 4468 | Otc Investors Inc | Locust Grove, OK 74352 | Oil Operator | Jan 2025 |
| 4469 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 4470 | Otc/Occ Not Assigned | | Oil & Gas Operator | Dec 2024 |
| 4471 | Ouachita Exploration Inc | Chickasha, OK 73018 | Oil & Gas Operator | Jan 2025 |
| 4472 | Outback Petroleum Inc | Moore, OK 73160-9998 | Oil & Gas Operator | Mar 2015 |
| 4473 | Outlaw Oil And Gas LLC | Kaw City, OK 74641 | Oil & Gas Operator | Jan 2025 |
| 4474 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 4475 | Ovation Energy, LP | N Richlnd HLS, TX 76180 | Oil & Gas Operator | Sep 2004 |
| 4476 | Overflow Energy Stack LLC | Booker, TX 79005 | Oil Operator | Sep 2022 |
| 4477 | Overflow Energy, LLC | Booker, TX 79005 | Oil & Gas Operator | Apr 2025 |
| 4478 | Overland Investments Inc | Coweta, OK 74429 | Oil & Gas Operator | Jan 2025 |
| 4479 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Feb 2025 |
| 4480 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 4481 | Owens James W | Tulsa, OK 74114-1425 | Oil & Gas Operator | Oct 2022 |
| 4482 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 4483 | Oxco LLC | Pawhuska, OK 74056 | Oil & Gas Operator | Feb 2015 |
| 4484 | Oxford Exploration Company | Denver, CO 80237 | Oil & Gas Operator | Aug 1995 |
| 4485 | Oxford Oil Inc | Cleveland, OK 74020 | Oil & Gas Operator | Feb 1997 |
| 4486 | Oxley Energy LLC | Houston, TX 77042 | Gas Operator | Jan 2025 |
| 4487 | Oxley John C | Tulsa, OK 74103 | Oil & Gas Operator | Sep 1996 |
| 4488 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 4489 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 4490 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2025 |
| 4491 | Ozark Gas Gathering LLC | Fort Smith, AR 72916 | Oil & Gas Operator | Jan 2025 |
| 4492 | Ozark Oil Corporation | Springfield, MO 65804 | Oil & Gas Operator | Oct 1992 |
| 4493 | P & C Oil Company | Leona, TX 75850 | Oil & Gas Operator | Dec 2024 |
| 4494 | P & H Construction Inc | Wewoka, OK 74884 | Oil & Gas Operator | Jun 2024 |
| 4495 | P & H Oil & Gas Inc | Stroud, OK 74079 | Oil & Gas Operator | Feb 2025 |
| 4496 | P & M Drilling Company Inc | Depew, OK 74028 | Oil & Gas Operator | Dec 2004 |
| 4497 | P & M Petroleum Management | Denver, CO BAD ADDR | Oil & Gas Operator | Apr 2010 |
| 4498 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 4499 | P A Energy Inc | Calvin, OK 74531-0248 | Oil & Gas Operator | Apr 2020 |
| 4500 | P F Beeler LLC | Norman, OK 73072-7522 | Oil & Gas Operator | Feb 2025 |