- La Sagra's Flycatcher
- Lacrimose Mountain Tanager
- Lanceolated Monklet
- Lapland Longspur
- Large-footed Finch
- Lark Sparrow
- Laughing Falcon
- Laughing Gull
- Least Bittern
- Least Flycatcher
- Least Grebe
- Least Sandpiper
- Lemon-rumped Tanager
- Lesser Ground Cuckoo
- Lesser Kiskadee
- Lesser Nighthawk
- Lesser Scaup
- Lesser Yellow-headed Vulture
- Lesser Yellowlegs
- Limpkin
- Lincoln's Sparrow
- Lineated Woodpecker
- Little Blue Heron
- Little Tinamou
- Loggerhead Kingbird
- Long-billed Dowitcher
- Long-billed Hermit
- Long-tailed Duck
- Long-tailed Silky-flycatcher
- Long-tailed Sylph
- Long-tailed Tyrant
- Lyre-tailed Nightjar