- Laughing Dove
- Laughing Gull
- Laughing Kookaburra
- Least Bittern
- Least Flycatcher
- Least Grebe
- Least Sandpiper
- Lemon-rumped Tanager
- Lesser Black-backed Gull
- Lesser Flamingo
- Lesser Greenlet
- Lesser Masked Weaver
- Lesser Scaup
- Lesser Spotted Woodpecker
- Lesser Swamp Warbler
- Lesser Violetear
- Lesser Yellow-headed Vulture
- Lesson's Motmot
- Lewin's Honeyeater
- Lilac-breasted Roller
- Limpkin
- Lineated Foliage-gleaner
- Lineated Woodpecker
- Little Bee-eater
- Little Bittern
- Little Black Cormorant
- Little Blue Heron
- Little Corella
- Little Egret
- Little Grassbird
- Little Grebe
- Little Gull
- Little Owl
- Little Penguin
- Little Pied Cormorant
- Little Raven
- Little Ringed Plover
- Little Stint
- Little Wattlebird
- Little Weaver
- Long-crested Eagle
- Long-tailed Fiscal
- Long-tailed Tit
- Long-toed Lapwing
- Louisiana Waterthrush