Encyclopedias, Almanacs, Transcripts, and Maps
- longest rail and road tunnels
- longest rivers
- Lopez, Barry Holstun (1945 – ) American Environmental Writer
- Lophiiformes (Anglerfishes)
- Lophogastrida (Lophogastrids)
- Lord of the Animals
- Lords
- Loricifera (Girdle Wearers)
- Lorises and Pottos (Lorisidae)
- Los Angeles Basin
- Lovelock, Sir James Ephraim (1919 – ) English Chemist
- Lovins, Amory Bloch (1947 – ) American Physicist and Energy Conservationist
- Löw, Yehudah ben Betsal?el of Prague
- Low-Head Hydropower
- Low-Level Radioactive Waste
- Lower Metazoans, Lesser Deuterostomes, and Humans
- Lowest Achievable Emission Rate
- Lowry, L.S.
- Lu Xiangshan
- Lu Xiujing