Science magazines
- Least Tern
- Leatherback Sea Turtle
- Lee County Cave Isopod
- Lee Pincushion Cactus
- Leedy's Roseroot
- Leon Springs Pupfish
- Leopard Darter
- Lepanthes Eltoroensis
- Leptocereus Grantianus
- Lesser Long-nosed Bat
- Lewton's Polygala
- Light-footed Clapper Rail
- Liliwai
- Little Aguja Creek Pondweed
- Little Amphianthus
- Little Colorado Spinedace
- Little Kern Golden Trout
- Little Mariana Fruit Bat
- Littlewing Pearlymussel
- Lloyd's Hedgehog Cactus