- Lanceolated Warbler
- Lanner Falcon
- Large-billed Leaf Warbler
- Large-billed Tern
- Large-headed Flatbill
- Large-tailed Antshrike
- Large Elaenia
- Large Scrubwren
- Latham's Snipe
- Laysan Albatross
- Lazy Cisticola
- Leach's Storm Petrel
- Lear's Macaw
- Least Nighthawk
- Least Storm Petrel
- LeConte's Thrasher
- Lemon-rumped Warbler
- Lesser Bird-of-paradise
- Lesser Cuckoo
- Lesser Elaenia
- Lesser Flamingo
- Lesser Florican
- Lesser Grass Finch
- Lesser Green Leafbird
- Lesser Hornero
- Lesser Moorhen
- Lesser Nighthawk
- Lesser Rhea
- Lesser Seedcracker
- Lesser Striped Swallow
- Lesser Swamp Warbler
- Lesser Wagtail-Tyrant
- Levaillant's Woodpecker
- Light-crowned Spinetail
- Lilian's Lovebird
- Lincoln's Sparrow
- Line-cheeked Spinetail
- Line-fronted Canastero
- Lineated Foliage-gleaner
- Little Greenbul
- Little Nightjar
- Little Rush Warbler
- Little Spotted Woodpecker
- Little Wattlebird
- Little Woodstar
- Little Yellow Flycatcher
- Livingstone's Flycatcher
- Lompobattang Flycatcher
- Long-billed Bernieria
- Long-billed Corella
- Long-billed Forest Warbler
- Long-billed Murrelet
- Long-billed Pipit
- Long-billed Plover
- Long-billed Woodcreeper
- Long-billed Wren
- Long-billed Wren-Babbler
- Long-crested Pygmy Tyrant
- Long-tailed Ground Roller
- Long-tailed Hermit
- Long-tailed Honey Buzzard
- Long-tailed Minivet
- Long-tailed Paradigalla
- Long-tailed Parakeet
- Long-tailed Reed Finch
- Long-tailed Sabrewing
- Long-tailed Shrike
- Long-tailed Widowbird
- Long-toed Stint
- Long-trained Nightjar
- Long-tufted Screech Owl
- Long-whiskered Owlet
- Long-winged Antwren
- Long-winged Harrier
- Lorentz's Whistler
- Lowland Masked Apalis
- Luapula Cisticola
- Lühder's Bushshrike
- Lyre-tailed Nightjar