| Abbreviation | Definition |
|---|---|
| LSF | Lynden Scholarship Foundation |
| LSFI | Life Science Foundation India |
| LSLF | Lauri Strauss Leukemia Foundation |
| LSRF | Life Sciences Research Foundation |
| LSSF | Lions Save Sight Foundation |
| LSSF | Lumbini Social Service Foundation |
| LSYF | Lighthouse Sanctuary Youth Foundation (Georgia) |
| LTCF | Lawrence Township Community Foundation |
| LTEF | Lake Tahoe Educational Foundation |
| LTEF | Lake Thunderbird Educational Foundation |
| LTEF | Lake Travis Education Foundation |
| LTEF | Lawrence Township Education Foundation |
| LTF | Laying the Foundation |
| LTMF | Loves Top Models Foundation |
| LUAF | Looking Up Arts Foundation |
| LUF | Living Universe Foundation |
| LVEF | Las Virgenes Educational Foundation |
| LVEF | Livermore Valley Education Foundation |
| LWAF | Lake Wilderness Arboretum Foundation (Maple Valley, WA) |
| LWEF | Lake Worth Education Foundation |