- Mackinnon's Shrike
- Magenta-throated Woodstar
- Magnificent Frigatebird
- Magpie Starling
- Magpie Tanager
- Maguari Stork
- Malachite Kingfisher
- Mallard
- Mangrove Swallow
- Marabou Stork
- Marble-faced Bristle Tyrant
- Marsh Sandpiper
- Marsh Tit
- Marsh Warbler
- Martial Eagle
- Masked Cardinal
- Masked Crimson Tanager
- Masked Flowerpiercer
- Masked Gnatcatcher
- Masked Saltator
- Masked Tityra
- Masked Trogon
- Masked Water Tyrant
- Masked Yellowthroat
- Mato Grosso Antbird
- Melodious Warbler
- Meyer's Parrot
- Middle Spotted Woodpecker
- Mistle Thrush
- Monk Parakeet
- Montagu's Harrier
- Montane Foliage-gleaner
- Montane Woodcreeper
- Montezuma Oropendola
- Mosque Swallow
- Mountain Elaenia
- Mountain Oriole
- Mountain Wagtail
- Mountain Wren
- Mourning Collared Dove
- Moustached Grass Warbler
- Moustached Puffbird
- Muscovy Duck
- Mute Swan