- Macaroni Penguin
- MacGregor's Honeyeater
- Mackinnon's Shrike
- Macleay's Honeyeater
- Macqueen's Bustard
- Madagascar Blue Pigeon
- Madagascar Blue Vanga
- Madagascar Buttonquail
- Madagascar Buzzard
- Madagascar Cisticola
- Madagascar Cuckoo
- Madagascar Cuckooshrike
- Madagascar Fish Eagle
- Madagascar Flufftail
- Madagascar Forest Rail
- Madagascar Grebe
- Madagascar Green Pigeon
- Madagascar Harrier-Hawk
- Madagascar Hoopoe
- Madagascar Ibis
- Madagascar Jacana
- Madagascar Lark
- Madagascar Magpie-Robin
- Madagascar Mannikin
- Madagascar Martin
- Madagascar Nightjar
- Madagascar Owl
- Madagascar Partridge
- Madagascar Plover
- Madagascar Pochard
- Madagascar Pratincole
- Madagascar Pygmy Kingfisher
- Madagascar Rail
- Madagascar Sandgrouse
- Madagascar Snipe
- Madagascar Sparrowhawk
- Madagascar Spinetail
- Madagascar Starling
- Madagascar Stonechat
- Madagascar Swamp Warbler
- Madagascar Wagtail
- Madeira Chaffinch
- Madeira Firecrest
- Magellanic Oystercatcher
- Magellanic Penguin
- Magnificent Bird-of-paradise
- Magnificent Frigatebird
- Magnificent Riflebird
- Magnolia Warbler
- Magpie-lark
- Magpie Goose
- Magpie Mannikin
- Magpie Shrike
- Magpie Starling
- Magpie Tanager
- Maguari Stork
- Malabar Barbet
- Malabar Grey Hornbill
- Malabar Lark
- Malabar Pied Hornbill
- Malabar Starling
- Malabar Trogon
- Malabar Whistling Thrush
- Malabar Woodshrike
- Malachite Kingfisher
- Malachite Sunbird
- Malagasy Black Swift
- Malagasy Brush Warbler
- Malagasy Bulbul
- Malagasy Coucal
- Malagasy Green Sunbird
- Malagasy Harrier
- Malagasy Kestrel
- Malagasy Kingfisher
- Malagasy Palm Swift
- Malagasy Paradise Flycatcher
- Malagasy Pond Heron
- Malagasy Sacred Ibis
- Malagasy Turtle Dove
- Malagasy White-eye
- Malaita Owl
- Malaita White-eye
- Malayan Banded Pitta
- Malayan Swamp Babbler
- Malaysian Blue Flycatcher
- Malaysian Eared Nightjar
- Malaysian Honeyguide
- Malaysian Pied Fantail
- Malaysian Plover
- Malherbe's Parakeet
- Malia
- Malindi Pipit
- Mallard
- Mallee Emu-wren
- Malleefowl
- Mandarin Duck
- Maned Duck
- Mangrove Cuckoo
- Mangrove Fantail
- Mangrove Gerygone
- Mangrove Honeyeater
- Mangrove Hummingbird
- Mangrove Kingfisher
- Mangrove Pitta
- Mangrove Robin
- Mangrove Sunbird
- Mangrove Swallow
- Mangrove Vireo
- Mangrove Warbler
- Mangrove Whistler
- Manipur Fulvetta
- Mantanani Scops Owl
- Manx Shearwater
- Many-banded Aracari
- Many-colored Chaco Finch
- Many-colored Rush Tyrant
- Many-spotted Hummingbird
- Many-striped Canastero
- Marabou Stork
- Maranon Pigeon
- Maranon Thrush
- Marble-faced Bristle Tyrant
- Marbled Duck
- Marbled Frogmouth
- Marbled Godwit
- Marico Flycatcher
- Marico Sunbird
- Marigold Lorikeet
- Maroon-backed Accentor
- Maroon-bellied Parakeet
- Maroon-breasted Philentoma
- Maroon-tailed Parakeet
- Maroon Oriole
- Maroon Woodpecker
- Marsh Babbler
- Marsh Owl
- Marsh Sandpiper
- Marsh Tchagra
- Marsh Tit
- Marshall's Iora
- Martens's Warbler
- Martial Eagle
- Marvelous Spatuletail
- Mascarene Martin
- Masked Booby
- Masked Bowerbird
- Masked Crimson Tanager
- Masked Finch
- Masked Flowerpiercer
- Masked Gnatcatcher
- Masked Lapwing
- Masked Shrike
- Masked Tanager
- Masked Tityra
- Masked Trogon
- Masked Water Tyrant
- Masked Woodswallow
- Maxwell's Black Weaver
- Mayotte Drongo
- Mayotte Sunbird
- Mayotte White-eye
- McGregor's Cuckooshrike
- Meadow Bunting
- Meadow Pipit
- Mealy Amazon
- Mediterranean Short-toed Lark
- Medium Egret
- Medium Ground Finch
- Mees's White-eye
- Melancholy Woodpecker
- Melanesian Kingfisher
- Meller's Duck
- Melodious Babbler
- Melodious Blackbird
- Metallic-green Tanager
- Metallic-winged Sunbird
- Metallic-winged Sunbird (jefferyi)
- Metallic Pigeon
- Metallic Starling
- Meves's Starling
- Mexican Cacique
- Mexican Chickadee
- Mexican Violetear
- Meyer's Parrot
- Mid-mountain Berrypecker
- Middle Spotted Woodpecker
- Midget Flowerpecker
- Mimic Honeyeater
- Mindanao Boobook
- Mindanao Hornbill
- Miombo Blue-eared Starling
- Miombo Pied Barbet
- Miombo Rock Thrush
- Miombo Tit
- Miombo Wren-Warbler
- Mishmi Wren-Babbler
- Mistle Thrush
- Mistletoe Tyrannulet
- Mistletoebird
- Mitred Parakeet
- Mocking Cliff Chat
- Moheli White-eye
- Moluccan Eclectus
- Moluccan Flycatcher
- Moluccan Hanging Parrot
- Moluccan Megapode
- Moluccan Monarch
- Moluccan Owlet-nightjar
- Moluccan Scops Owl
- Moluccan Starling
- Mombasa Woodpecker
- Mongolian Finch
- Mongolian Ground Jay
- Mongolian Lark
- Monk Parakeet
- Monotonous Lark
- Montagu's Harrier
- Montane Foliage-gleaner
- Montane Widowbird
- Montane Woodcreeper
- Monteiro's Bushshrike
- Montezuma Oropendola
- Moorland Chat
- Moreau's Sunbird
- Morelet's Seedeater
- Morepork
- Mosque Swallow
- Moss-backed Sparrow
- Mottle-cheeked Tyrannulet
- Mottled Owl
- Mottled Swift
- Mottled Wood Owl
- Mountain Barbet
- Mountain Blackeye
- Mountain Bluebird
- Mountain Bulbul
- Mountain Buzzard
- Mountain Caracara
- Mountain Chickadee
- Mountain Elaenia
- Mountain Greenbul
- Mountain Hawk-Eagle
- Mountain Illadopsis
- Mountain Imperial Pigeon
- Mountain Leaf Warbler
- Mountain Oriole
- Mountain Owlet-nightjar
- Mountain Peltops
- Mountain Plover
- Mountain Pygmy Owl
- Mountain Robin
- Mountain Serpent Eagle
- Mountain Shrike
- Mountain Tailorbird
- Mountain Thrush
- Mountain Trogon
- Mountain Velvetbreast
- Mountain Wagtail
- Mountain Wheatear
- Mountain Wren
- Mountain Wren-Babbler
- Mountain Yellow Warbler
- Mourning Babbler
- Mourning Collared Dove
- Mourning Dove
- Mourning Sierra Finch
- Mouse-colored Penduline Tit
- Moussier's Redstart
- Moustached Babbler
- Moustached Flowerpiercer
- Moustached Grass Warbler
- Moustached Laughingthrush
- Moustached Tinkerbird
- Moustached Treeswift
- Moustached Wren
- Mrs. Gould's Sunbird
- Muisca Antpitta
- Mulga Parrot
- Multicolored Tanager
- Muscovy Duck
- Musk Duck
- Musk Lorikeet
- Mute Swan
- Myrtle Warbler