| Liquefaction Exp and P/L Ext and Exp Proj | Cheniere Creole Trail Pipeline, L.P. | LA | | |
| Liquefied Natural Gas Meter Project | Great Basin Gas Transmission Company | NV | | |
| Little Missouri Gas Plant Expansion - McKenzie | Targa Badlands LLC | ND | | |
| Little Missouri River Crossing - Billings County | Tesoro - High Plains Pipeline Company | ND | | |
| Little Muddy Creek Pipeline & Epping Station Pjct | Meadowlark Midstream Company, LLC | ND | | |
| Livingston Parish Project | Florida Gas Transmission Company, LLC | LA, MS | Started 2024 | |
| Llog Exploration coastal use permit P20100869 pipeline | Llog Exploration Co | LA | | |
| Llox coastal use permit P20220889 pipeline | Llox, LLC | LA | | |
| Lobo Operating coastal use permit P19990377 pipeline | Lobo Operating, Inc. | LA | | |
| Lobo Operating coastal use permit P19991464 pipeline | Lobo Operating, Inc. | LA | | |
| Lobo Operating coastal use permit P20010168 pipeline | Lobo Operating, Inc. | LA | | |
| Lobo Operating coastal use permit P20011486 pipeline | Lobo Operating, Inc. | LA | | |
| Lobo Operating coastal use permit P20011682 pipeline | Lobo Operating, Inc. | LA | | |
| Locap coastal use permit P19970971 pipeline | Locap Inc | LA | | |
| Locke LP Pipeline | | WV | | |
| Lockridge Extension Project | Natural Gas Pipeline Company of America | TX | In service 2020 | |
| Lodi (Kirby Hills) Lateral | Lodi Storage Inc | CA | In service 2006 | |
| Lodi Gas Storage System Phase 2 Project | | CA | In service 2009 | |
| Lodi Storage Field Lateral | Lodi Storage Inc | CA | In service 2001 | |
| Logan Compressor and Regulating Station (Trailblazer Conversion Project) | Rockies Express Pipeline LLC | CO | 2024 | |
| Logan Lateral | Texas Eastern Transmission, LP | NJ, PA | | |
| Logansport Well Installation Project | Equitrans, L.P. | | | |
| Lone Oak Compressor Station (Mountaineer XPress addition) | Columbia Gas Transmission, LLC | WV | | |
| Lone Star Express Expansion | Energy Transfer | TX | In service 2020 | |
| Lone Star Express Pipeline | Energy Transfer Partners | TX | In service 2016 | |
| Lone Star Project | Tennessee Gas Pipeline Company, L.L.C. | TX | 2018 | |
| Lonerock Pipeline | | OK | | |
| Lonesome Creek Gas Plant - McKenzie County | Oneok Rockies Midstream, LLC | ND | | |
| Lonesome Creek Gas Plant - McKenzie County, ND | Oneok Rockies Midstream, LLC | ND | | |
| Lonesome Creek NGL Pipeline Pjct - McKenzie | ONEOK Bakken Pipeline, L.L.C. | ND | In service 2015 | |