- Madeira Firecrest
- Magenta-throated Woodstar
- Magnificent Frigatebird
- Magpie Shrike
- Magpie Tanager
- Malaysian Pied Fantail
- Malaysian Plover
- Mallard
- Mandarin Duck
- Mangrove Warbler
- Mangrove Whistler
- Many-banded Aracari
- Many-colored Chaco Finch
- Many-colored Rush Tyrant
- Many-spotted Hummingbird
- Marabou Stork
- Maranon Thrush
- Marble-faced Bristle Tyrant
- Marico Flycatcher
- Marsh Sandpiper
- Marsh Tit
- Martial Eagle
- Masked Crimson Tanager
- Masked Flowerpiercer
- Masked Gnatcatcher
- Masked Laughingthrush
- Masked Shrike
- Masked Trogon
- Masked Water Tyrant
- Masked Yellowthroat
- Meadow Bunting
- Meadow Pipit
- Mealy Amazon
- Medium Egret
- Melodious Warbler
- Merlin
- Meves's Starling
- Mexican Violetear
- Mistle Thrush
- Mocking Cliff Chat
- Monk Parakeet
- Montagu's Harrier
- Montane Woodcreeper
- Monteiro's Hornbill
- Montezuma Oropendola
- Mottled Owl
- Mountain Bulbul
- Mountain Caracara
- Mountain Imperial Pigeon
- Mountain Wheatear
- Mountain Wren
- Mouse-colored Thistletail
- Mouse-grey Flycatcher
- Moussier's Redstart
- Moustached Antpitta
- Moustached Barbet
- Moustached Warbler
- Mugimaki Flycatcher
- Muisca Antpitta