- MacGillivray's Warbler
- Macleay's Honeyeater
- Magnificent Frigatebird
- Magpie-lark
- Magpie Goose
- Magpie Shrike
- Malagasy Pond Heron
- Malagasy Turtle Dove
- Mallard
- Maned Duck
- Mangrove Cuckoo
- Mangrove Rail
- Mangrove Robin
- Marabou Stork
- Marsh Tit
- Martial Eagle
- Masked Finch
- Masked Lapwing
- Masked Tityra
- Masked Woodswallow
- Masked Yellowthroat
- Mayotte Drongo
- McConnell's Flycatcher
- Melanesian Flycatcher
- Merlin
- Metallic Pigeon
- Metallic Starling
- Mew Gull
- Mistletoebird
- Mountain Bluebird
- Mountain Caracara
- Mountain Chickadee
- Mourning Collared Dove
- Mourning Dove
- Mouse-colored Antshrike
- Mouse-colored Tyrannulet
- Mulga Parrot
- Muscovy Duck
- Musician Wren
- Musk Duck
- Mute Swan