- Lapland Longspur
- Laughing Dove
- Laughing Gull
- Laughing Kookaburra
- Least Sandpiper
- Lesser Black-backed Gull
- Lesser Grey Shrike
- Lesser Kestrel
- Lesser Redpoll
- Lesser Whistling Duck
- Lesser White-fronted Goose
- Lesser Whitethroat
- Lesser Yellow-headed Vulture
- Lesser Yellowlegs
- Lilac-crowned Amazon
- Lined Seedeater
- Little Bittern
- Little Blue Heron
- Little Bunting
- Little Bustard
- Little Cormorant
- Little Crake
- Little Cuckoo
- Little Egret
- Little Grebe
- Little Owl
- Little Pied Cormorant
- Little Ringed Plover
- Little Spiderhunter
- Little Stint
- Little Tern
- Little Woodpecker
- Long-legged Buzzard
- Long-tailed Duck
- Long-tailed Finch
- Long-tailed Jaeger
- Long-tailed Shrike
- Long-tailed Tit
- Long-tailed Tyrant
- Lord Derby's Parakeet
- Luzon Bleeding-heart