- Lacrimose Mountain Tanager
- Lafresnaye's Vanga
- Lanner Falcon
- Lapland Longspur
- Lappet-faced Vulture
- Large-billed Tern
- Large-footed Finch
- Large-tailed Nightjar
- Large Grey Babbler
- Large Scimitar Babbler
- Laughing Dove
- Laughing Gull
- Laurel Pigeon
- Lavender Waxbill
- Least Bittern
- Least Flycatcher
- Least Sandpiper
- Lemon-bellied Crombec
- Lemon Dove
- Lesser Adjutant
- Lesser Antillean Bullfinch
- Lesser Antillean Swift
- Lesser Black-backed Gull
- Lesser Black-backed Gull (heuglini)
- Lesser Blue-eared Starling
- Lesser Elaenia
- Lesser Flamingo
- Lesser Goldfinch
- Lesser Greenlet
- Lesser Grey Shrike
- Lesser Kestrel
- Lesser Kiskadee
- Lesser Necklaced Laughingthrush
- Lesser Noddy
- Lesser Scaup
- Lesser Spotted Eagle
- Lesser Spotted Woodpecker
- Lesser Striped Swallow
- Lesser Swallow-tailed Swift
- Lesser Swamp Warbler
- Lesser Vasa Parrot
- Lesser Violetear
- Lesser Whistling Duck
- Lesser Whitethroat
- Lesser Yellow-headed Vulture
- Lesser Yellowlegs
- Lesson's Motmot
- Levaillant's Cuckoo
- Lilac-breasted Roller
- Limpkin
- Lineated Woodpecker
- Little Bee-eater
- Little Bittern
- Little Blue Heron
- Little Bustard
- Little Chachalaca
- Little Cormorant
- Little Crake
- Little Egret
- Little Grebe
- Little Greenbul
- Little Grey Greenbul
- Little Gull
- Little Owl
- Little Pied Cormorant
- Little Ringed Plover
- Little Rock Thrush
- Little Stint
- Little Swift
- Little Tern
- Little Weaver
- Little Woodpecker
- Lizard Buzzard
- Long-billed Bernieria
- Long-billed Curlew
- Long-billed Pipit
- Long-crested Eagle
- Long-eared Owl
- Long-legged Buzzard
- Long-tailed Broadbill
- Long-tailed Duck
- Long-tailed Fiscal
- Long-tailed Glossy Starling
- Long-tailed Ground Roller
- Long-tailed Nightjar
- Long-tailed Paradise Whydah
- Long-tailed Shrike
- Long-tailed Silky-flycatcher
- Long-tailed Sylph
- Long-tailed Tit
- Long-tailed Tyrant
- Long-toed Lapwing
- Long-toed Stint
- Long-winged Harrier
- Longuemare's Sunangel
- Louisiana Waterthrush
- Lyre-tailed Nightjar