| Oneok North System Lemont terminal | Terminal | IL | Oneok North System LLC | |
| Oneok North System Morris terminal | Terminal | IL | Oneok North System LLC | |
| Oneok North System Plattsmouth terminal | Terminal | NE | Oneok North System LLC | |
| Oneok North System Rockford terminal | Terminal | IL | Oneok North System LLC | |
| Oneok North System Tampico terminal | Terminal | IL | Oneok North System LLC | |
| Oneok North System Wichita terminal | Terminal | KS | Oneok North System LLC | |
| Oneok Rockies Midstream Riverview terminal | Terminal | MT | Oneok Rockies Midstream, LLC | |
| Onion Prairie Compressor Station | Compressor station | Osage County, OK | Osage Hills Pipeline Company, LLC | |
| Op Reno Sparks terminal | Terminal | NV | Op Reno LLC | |
| Opal Compressor Station | Compressor station | Blaine County, OK | Enlink Midstream Services, LLC | |
| Opal Gas Plant | Gas processing plant | Lincoln County, WY | Williams Field Services Company, Williams Midstream Services, LLC | In service |
| Optima Compressor Station | Compressor station | Texas County, OK | DCP Operating Company, LP | |
| Orbit Ethane Export terminal | Terminal | TX | Orbit Gulf Coast NG Exports LLC | |
| Oregon Basin Gas Plant | Gas processing plant | Park County, WY | Marathon Oil Company, Merit Energy Company | In service |
| Orienta Compressor Station | Compressor station | Major County, OK | Targa Pipeline Midcontinent Westok LLC | |
| Orion Booster Station | Compressor station | Dewey County, OK | DCP Operating Company, LP | |
| Orla Cryogenic Natural Gas Plant | Gas processing plant | Reeves County, TX | | |
| Orla East | Gas processing plant | Reeves County, TX | | |
| Orla Plant | Gas processing plant | Reeves County, TX | ETC Texas Pipeline, Ltd. | In service |
| Orlando Compressor Station | Compressor station | Noble County, OK | ET Gathering & Processing, LLC | |
| Oryx 33 Compressor Station | Compressor station | Roger Mills County, OK | Palo Duro Pipelines (texas Gathering), L.p. | |
| Osage Compressor Station | Compressor station | Osage County, OK | Osage Hills Pipeline Company, LLC | |
| Osage Hills Gas Plant | Gas processing plant | Osage County, OK | Alex Gas Systems | In service |
| Osborne Plant | Gas processing plant | Roberts County, TX | Enbridge Pipelines (texas Gathering) Inc. | In service |
| Otero CS - Beeline Gas Systems | Compressor station | NM | Beeline Gas Systems | |
| Otter Creek Midstream Perry Compressor Station | Compressor station | Noble County, OK | Otter Creek Midstream | |
| Overisel | Underground storage | Allegan County, MI | Consumers Energy Inc | In service |
| Overton Drip Station | Gas processing plant | Cherokee County, TX | | |
| Owens 1 CDP | Compressor station | NM | Hilcorp Energy Company | |
| Owens Corning Irving Asphalt Plant terminal | Terminal | TX | Owens Corning | |
| Owens Corning Oklahoma City Asphalt Plant terminal | Terminal | OK | Owens Corning | |
| Owens Corning Roofing & Asphalt Div Of Owens Corni terminal | Terminal | CA | Owens Corning | |
| Owens Corning Summit Asphalt Plant terminal | Terminal | IL | Owens Corning | |
| Oxbow Compressor Station | Compressor station | Roger Mills County, OK | ET Gathering & Processing, LLC | |
| Oxy CO2 Plant - Bravo Dome | Gas processing plant | NM | Oxy USA Inc | |
| Oxy Indian Basin GP | Gas processing plant | NM | Oxy USA Inc | |
| Oxy Permian C02 Recompression Facility | Gas processing plant | NM | Occidental Permian Limited Partnership | |
| Oxy USA Indian Basin Gas Plant | Gas processing plant | NM | Oxy USA Inc | |
| Oxy USA WTP Indian Basin Gas Plant | Gas processing plant | NM | Oxy Usa Wtp LP | |
| Ozark Gas Transmission Lequire Compressor Station | Compressor station | Haskell County, OK | Ozark Gas Transmission Co | |
| Ozona | Gas processing plant | Crockett County, TX | Chevron | In service |
| Ozona Gas Processing Plant | Gas processing plant | Crockett County, TX | DCP Operating Company, LP | In service |
| PBF Logistics Products Terminals 4715 Knoxville | Terminal | TN | PBF Logistics Products Terminals LLC | |
| PBF Logistics Products Terminals 5100 Knoxville | Terminal | TN | PBF Logistics Products Terminals LLC | |
| PBF Logistics Products Terminals North Philadelphia | Terminal | PA | PBF Logistics Products Terminals LLC | |
| PBF Logistics Products Terminals Paulsboro | Terminal | NJ | PBF Logistics Products Terminals LLC | |
| PBF Logistics Products Terminals Philadelphia - 51st Street | Terminal | PA | PBF Logistics Products Terminals LLC | |
| PBF Logistics Products Terminals South Philadelphia | Terminal | PA | PBF Logistics Products Terminals LLC | |
| PBF Logistics Products Terminals Toledo | Terminal | OH | PBF Logistics Products Terminals LLC | |
| PBF T&m Terminal T&m Terminal Pipeline CO | Terminal | MS | PBF T&m Terminal | |