| LNG Supply Pipeline Capacity Increase Project | Ecoelectrica L.p. | | | |
| LNG Supply Pipeline Project | Ecoelectrica L.p. | PR | In service 2022 | |
| LP Mineral Pipeline Relocation Project | Dominion Hope Gas Inc | WV | | |
| La Intrastate Gas coastal use permit P19971857 pipeline | La Intrastate Gas CO | LA | | |
| La Land & Expl coastal use permit P19961500 pipeline | La Land & Expl | LA | | |
| La Resources Pipelin coastal use permit P19980612 pipeline | La Resources Pipelin | LA | | |
| La Storage coastal use permit P20080450 pipeline | La Storage, LLC | LA | | |
| La Storage coastal use permit P20141071 pipeline | La Storage, LLC | LA | | |
| LaCrosse Branch Loop 2003 | | MN | | |
| LaCrosse Pipeline Project | Enbridge Pipelines (LaCrosse) L.L.C. | | | |
| LaCrosse/Tomah Expansion Project | Northern Natural Gas Company | IA, MN | Started 2008 | |
| LaGrange Horsepower Replacement Project | ANR Pipeline Company | IN | In service 2016 | |
| LaPorte to Gary Aetna Natural Gas Line Upgrade | | IN | | |
| LaSalle Residue Line Project | DCP Midstream, LP | CO | | |
| Lake Charles Expansion Proj | Kinder Morgan Louisiana Pipeline Company LLC | LA | | |
| Lake Charles LNG | Trunkline LNG Co | LA | | |
| Lake City 1st Branch Line Abandonment and Capacity Replacement Project | Northern Natural Gas Company | IA | In service 2022 | |
| Lake Mills Compressor Station | | IA | | |
| Lake Mills Project | Northern Natural Gas Company | IA | | |
| Lake Raccourci Gathe coastal use permit P20000317 pipeline | Lake Raccourci Gathe | LA | | |
| Lake Raccourci Gathering System coastal use permit P20020735 pipeline | Lake Raccourci Gathering System, Inc | LA | | |
| Lakeshore Capacity Improvement Project (PCIP) | Wisconsin Electric Gas Operations | WI | In service 2020 | |
| Lakeshore Lateral Project (LLP) | Wisconsin Electric Gas Operations | WI | 2020–2021 | |
| Lamar County Expansion Project | Gulf South Pipeline Company, LLC | MS | In service 2021 | |
| Lambert Compressor Station | | VA | | |
| Lambertville Alternative Emissions Limit (AEL) Project | Texas Eastern Transmission, LP | NJ | | |
| Lambertville East Expansion Project | Texas Eastern Transmission, LP | NJ | 2019 | |
| Lancaster to Fort Lupton Pipeline | Xcel Energy | CO | | |
| Lanes Crossing Meter Station Project | Kern River Gas Transmission Company | CA | | |
| Laramie County Pipeline | Saddlehorn Pipeline LLC | WY | | |