| LAN | Local Area Network |
| LEO | Low Earth Orbit (satellite) |
| LF | Low Frequency (30 to 300 kHz) |
| LHC | Left Hand Circular |
| LM | Land Mobile Service |
| LMS | Land Mobile Service |
| LMSS | Land Mobile-Satellite Service |
| LMST | Light-Weight Multi-Band Satellite Terminal |
| LOFAR | Low Frequency Array |
| LPD | Low Power Device |
| LSI | Large Scale Integration |