- Cabot's Tern
- Cabot's Tern (eurygnathus)
- Campina Thrush
- Canada Goose
- Canary Islands Chiffchaff
- Canvasback
- Cape Barren Goose
- Cape Cormorant
- Cape Crow
- Cape Gannet
- Cape May Warbler
- Cape Sparrow
- Cape Teal
- Cape Wagtail
- Cape Weaver
- Carib Grackle
- Caribbean Elaenia
- Caribbean Martin
- Carrion Crow
- Caspian Gull
- Caspian Tern
- Cave Swiftlet
- Cetti's Warbler
- Chestnut-eared Aracari
- Chilean Flamingo
- Chiloe Wigeon
- Chinese Egret
- Chinese Pond Heron
- Cinnamon-bellied Saltator
- Cinnamon-breasted Bunting
- Cinnamon Becard
- Cinnamon Hummingbird
- Cirl Bunting
- Citrine Wagtail
- Clay-colored Thrush
- Coal Tit
- Cockatiel
- Cocoi Heron
- Coconut Lorikeet
- Collared Aracari
- Collared Kingfisher
- Collared Plover
- Collared Pratincole
- Common Blackbird
- Common Bulbul
- Common Buzzard
- Common Chiffchaff
- Common Crane
- Common Cuckoo
- Common Eider
- Common Emerald Dove
- Common Firecrest
- Common Flameback
- Common Gallinule
- Common Goldeneye
- Common Grackle
- Common Greenshank
- Common Ground Dove
- Common Gull
- Common Hill Myna
- Common Kestrel
- Common Kestrel (canariensis)
- Common Kingfisher
- Common Linnet
- Common Loon
- Common Merganser
- Common Moorhen
- Common Murre
- Common Myna
- Common Nightingale
- Common Ostrich
- Common Pheasant
- Common Pochard
- Common Quail
- Common Redshank
- Common Redstart
- Common Reed Bunting
- Common Reed Warbler
- Common Ringed Plover
- Common Sandpiper
- Common Shelduck
- Common Snipe
- Common Starling
- Common Swift
- Common Tailorbird
- Common Tern
- Common Waxbill
- Common Whitethroat
- Common Wood Pigeon
- Coppersmith Barbet
- Corsican Finch
- Cory's Shearwater
- Cotton Pygmy Goose
- Crested Barbet
- Crested Caracara (cheriway)
- Crested Drongo
- Crested Guan
- Crested Honey Buzzard
- Crested Lark
- Crested Oropendola
- Crested Pigeon
- Crested Tit
- Crimson-backed Tanager
- Croaking Cisticola
- Crowned Cormorant
- Cuban Blackbird
- Cuban Crow
- Cuban Emerald
- Cuban Grassquit
- Cuban Pewee
- Curlew Sandpiper