- Maccoa Duck
- Magellanic Snipe
- Magnificent Frigatebird
- Magpie Shrike
- Maguari Stork
- Malachite Kingfisher
- Malachite Sunbird
- Malaysian Pied Fantail
- Mallard
- Mandarin Duck
- Mangrove Kingfisher
- Mangrove Warbler
- Marabou Stork
- Marico Flycatcher
- Marico Sunbird
- Maroon Oriole
- Marsh Sandpiper
- Marsh Tit
- Martial Eagle
- Masked Cardinal
- Masked Flowerpiercer
- Masked Laughingthrush
- Masked Trogon
- Meadow Bunting
- Meadow Pipit
- Mealy Amazon
- Mediterranean Gull
- Medium Ground Finch
- Melodious Warbler
- Meves's Starling
- Mexican Violetear
- Meyer's Parrot
- Mocking Cliff Chat
- Mongolian Finch
- Monotonous Lark
- Montagu's Harrier
- Monteiro's Hornbill
- Moorland Chat
- Mottle-backed Elaenia
- Mottled Owl
- Mountain Bluebird
- Mountain Bulbul
- Mountain Chat
- Mountain Hawk-Eagle
- Mountain Imperial Pigeon
- Mountain Wagtail
- Mourning Collared Dove
- Mourning Sierra Finch
- Moustached Grass Warbler
- Mrs. Gould's Sunbird
- Muscovy Duck
- Mute Swan