- Lacrimose Mountain Tanager
- Ladder-backed Woodpecker
- Ladder-tailed Nightjar
- Lady Amherst's Pheasant
- Lafresnaye's Piculet
- Lafresnaye's Vanga
- Lance-tailed Manakin
- Lanceolated Monklet
- Lanceolated Warbler
- Lanner Falcon
- Lapland Longspur
- Lappet-faced Vulture
- Large-billed Antwren
- Large-billed Crow
- Large-billed Gerygone
- Large-billed Lark
- Large-billed Leaf Warbler
- Large-billed Scrubwren
- Large-billed Seed Finch
- Large-billed Tern
- Large-footed Finch
- Large-headed Flatbill
- Large-tailed Nightjar
- Large Blue Flycatcher
- Large Elaenia
- Large Frogmouth
- Large Grey Babbler
- Large Ground Finch
- Large Hawk-Cuckoo
- Large Niltava
- Large Rock Martin
- Large Scimitar Babbler
- Large Tree Finch
- Large Woodshrike
- Lark-like Brushrunner
- Lark-like Bunting
- Lark Sparrow
- Latham's Francolin
- Latham's Snipe
- Laughing Dove
- Laughing Falcon
- Laughing Gull
- Laughing Kookaburra
- Lava Gull
- Lava Heron
- Lavender Waxbill
- Lawrence's Thrush
- Layard's Parakeet
- Layard's Warbler
- Lazuline Sabrewing
- Leaden Flycatcher
- Leaf Lorikeet
- Least Bittern
- Least Flycatcher
- Least Grebe
- Least Sandpiper
- Least Seedsnipe
- Legge's Flowerpecker
- Lemon-bellied Crombec
- Lemon-bellied Flyrobin
- Lemon-bellied White-eye
- Lemon-breasted Canary
- Lemon-browed Flycatcher
- Lemon-chested Greenlet
- Lemon-rumped Tanager
- Lemon-rumped Warbler
- Lemon-spectacled Tanager
- Lemon-throated Leaf Warbler
- Lemon Dove
- Lesser Adjutant
- Lesser Bird-of-paradise
- Lesser Black-backed Gull
- Lesser Blue-eared Starling
- Lesser Coucal
- Lesser Crested Tern
- Lesser Cuckoo
- Lesser Cuckooshrike
- Lesser Elaenia
- Lesser Fish Eagle
- Lesser Flamingo
- Lesser Frigatebird
- Lesser Goldfinch
- Lesser Grass Finch
- Lesser Green Leafbird
- Lesser Greenlet
- Lesser Grey Shrike
- Lesser Ground Cuckoo
- Lesser Ground Robin
- Lesser Honeyguide
- Lesser Horned Owl
- Lesser Jacana
- Lesser Kestrel
- Lesser Kiskadee
- Lesser Masked Weaver
- Lesser Moorhen
- Lesser Necklaced Laughingthrush
- Lesser Nighthawk
- Lesser Prairie Chicken
- Lesser Racket-tailed Drongo
- Lesser Rhea
- Lesser Roadrunner
- Lesser Scaup
- Lesser Seedcracker
- Lesser Shortwing
- Lesser Spotted Woodpecker
- Lesser Striped Swallow
- Lesser Swamp Warbler
- Lesser Vasa Parrot
- Lesser Violetear
- Lesser Whistling Duck
- Lesser Whitethroat
- Lesser Woodcreeper
- Lesser Yellow-headed Vulture
- Lesser Yellowlegs
- Lesser Yellownape
- Lesson's Motmot
- Lettered Aracari
- Levaillant's Cisticola
- Levaillant's Cuckoo
- Lewin's Honeyeater
- Lewis's Woodpecker
- Lichtenstein's Sandgrouse
- Light-vented Bulbul
- Lilac-breasted Roller
- Lilian's Lovebird
- Limpkin
- Lincoln's Sparrow
- Line-cheeked Spinetail
- Line-fronted Canastero
- Lineated Barbet
- Lineated Woodpecker
- Lined Quail-Dove
- Lined Seedeater
- Lita Woodpecker
- Little Bee-eater
- Little Bittern
- Little Black Cormorant
- Little Blue Heron
- Little Bronze Cuckoo
- Little Bunting
- Little Chachalaca
- Little Corella
- Little Cormorant
- Little Crow
- Little Cuckoo
- Little Cuckoo-Dove
- Little Curlew
- Little Egret
- Little Forktail
- Little Friarbird
- Little Grassbird
- Little Grebe
- Little Green Sunbird
- Little Green Woodpecker
- Little Greenbul
- Little Grey Flycatcher
- Little Grey Greenbul
- Little Inca Finch
- Little Kingfisher
- Little Minivet
- Little Nightjar
- Little Owl
- Little Penguin
- Little Pied Cormorant
- Little Pied Flycatcher
- Little Raven
- Little Ringed Plover
- Little Rock Thrush
- Little Sparrowhawk
- Little Spiderhunter
- Little Spotted Woodpecker
- Little Stint
- Little Swift
- Little Tern
- Little Thornbird
- Little Wattlebird
- Little Weaver
- Little Woodpecker
- Little Woodstar
- Little Yellow Flycatcher
- Littoral Rock Thrush
- Livingstone's Flycatcher
- Livingstone's Turaco
- Lizard Buzzard
- Loggerhead Kingbird
- Loggerhead Shrike
- Lompobattang Leaf Warbler
- Long-billed Bernieria
- Long-billed Corella
- Long-billed Crombec
- Long-billed Crow
- Long-billed Curlew
- Long-billed Forest Warbler
- Long-billed Hermit
- Long-billed Pipit
- Long-billed Plover
- Long-billed Starthroat
- Long-billed Woodcreeper
- Long-billed Wren
- Long-billed Wren-Babbler
- Long-crested Eagle
- Long-legged Buzzard
- Long-legged Pipit
- Long-tailed Broadbill
- Long-tailed Bush Warbler
- Long-tailed Cisticola
- Long-tailed Duck
- Long-tailed Finch
- Long-tailed Fiscal
- Long-tailed Glossy Starling
- Long-tailed Ground Roller
- Long-tailed Hawk
- Long-tailed Jaeger
- Long-tailed Manakin
- Long-tailed Meadowlark
- Long-tailed Minivet
- Long-tailed Mockingbird
- Long-tailed Myna
- Long-tailed Nightjar
- Long-tailed Paradigalla
- Long-tailed Paradise Whydah
- Long-tailed Parakeet
- Long-tailed Shrike
- Long-tailed Sibia
- Long-tailed Silky-flycatcher
- Long-tailed Starling
- Long-tailed Sylph
- Long-tailed Thrush
- Long-tailed Tit
- Long-tailed Triller
- Long-tailed Tyrant
- Long-tailed Widowbird
- Long-toed Lapwing
- Long-toed Stint
- Long-whiskered Owlet
- Long-winged Harrier
- Lorentz's Whistler
- Loten's Sunbird
- Louisiana Waterthrush
- Lovely Sunbird
- Loveridge's Sunbird
- Lowland Akalat
- Lowland Peltops
- Lowland Sooty Boubou
- Lowland Tiny Greenbul
- Lowland White-eye
- Luapula Cisticola
- Ludwig's Bustard
- Ludwig's Double-collared Sunbird
- Lühder's Bushshrike
- Lulu's Tody-Flycatcher
- Luzon Boobook
- Luzon Flameback
- Luzon Hornbill
- Luzon Scops Owl
- Luzon Water Redstart
- Lynes's Cisticola
- Lyre-tailed Nightjar