- Calandra Lark
- California Gull
- California Quail
- California Scrub Jay
- California Towhee
- Campo Flicker
- Canada Goose
- Canada Jay
- Cape Barren Goose
- Cape Bunting
- Cape Crow
- Cape Petrel
- Cape Sparrow
- Cape Starling
- Cape Teal
- Cape Wagtail
- Cape Weaver
- Cape White-eye
- Capped Heron
- Capped Wheatear
- Cardinal Woodpecker
- Carp's Tit
- Carrion Crow
- Caspian Tern
- Cattle Tyrant
- Cetti's Warbler
- Chabert Vanga
- Chaco Chachalaca
- Chalk-browed Mockingbird
- Changeable Hawk-Eagle
- Chat Flycatcher
- Chestnut-and-black Weaver
- Chestnut-backed Chickadee
- Chestnut-backed Owlet
- Chestnut-backed Sparrow-Lark
- Chestnut-banded Plover
- Chestnut-bellied Guan
- Chestnut-bellied Sandgrouse
- Chestnut-bellied Starling
- Chestnut-eared Aracari
- Chestnut-fronted Macaw
- Chestnut-headed Bee-eater
- Chestnut-headed Sparrow-Lark
- Chestnut-naped Spurfowl
- Chestnut-vented Nuthatch
- Chestnut-vented Warbler
- Chestnut Teal
- Chestnut Weaver
- Chilean Flamingo
- Chilean Flicker
- Chilean Hawk
- Chilean Seaside Cinclodes
- Chilean Skua
- Chimango Caracara
- Chinspot Batis
- Chinstrap Penguin
- Chipping Sparrow
- Chocolate-backed Kingfisher
- Chopi Blackbird
- Chubb's Cisticola
- Chucao Tapaculo
- Chukar Partridge
- Cinereous Conebill
- Cinereous Vulture
- Cinnamon-breasted Bunting
- Cinnamon-chested Bee-eater
- Cinnamon Tanager
- Cirl Bunting
- Citril Finch
- Clamorous Reed Warbler
- Clark's Nutcracker
- Cliff Flycatcher
- Cliff Parakeet
- Coal Tit
- Cock-tailed Tyrant
- Cocoi Heron
- Collared Finchbill
- Collared Pratincole
- Collared Sunbird
- Comb-crested Jacana
- Common Babbler
- Common Black Hawk
- Common Blackbird
- Common Bronzewing
- Common Bulbul
- Common Buzzard
- Common Chiffchaff
- Common Crane
- Common Cuckoo
- Common Eider
- Common Emerald Dove
- Common Firecrest
- Common Gallinule
- Common Goldeneye
- Common Grackle
- Common Greenshank
- Common Gull
- Common Hawk-Cuckoo
- Common Iora
- Common Kestrel
- 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 Redpoll
- Common Redshank
- Common Redstart
- Common Reed Bunting
- Common Ringed Plover
- Common Rock Thrush
- Common Sandpiper
- Common Scimitarbill
- Common Shelduck
- Common Snipe
- Common Starling
- Common Swift
- Common Tailorbird
- Common Tern
- Common Wood Pigeon
- Common Yellowthroat
- Compact Weaver
- Congo Serpent Eagle
- Copper Sunbird
- Coppersmith Barbet
- Coppery-headed Emerald
- Coppery-tailed Coucal
- Coquerel's Coua
- Coqui Francolin
- Cordilleran Canastero
- Corn Bunting
- Cory's Shearwater
- Coscoroba Swan
- Cream-colored Courser
- Cream-winged Cinclodes
- Creamy-bellied Thrush
- Crested Barbet
- Crested Black Tyrant
- Crested Caracara
- Crested Caracara (cheriway)
- Crested Coua
- Crested Drongo
- Crested Duck
- Crested Francolin
- Crested Honey Buzzard
- Crested Kingfisher
- Crested Lark
- Crested Oropendola
- Crested Pigeon
- Crested Serpent Eagle
- Crested Tit
- Crested Treeswift
- Crimson-backed Flameback
- Crimson-breasted Shrike
- Crimson-fronted Barbet
- Crimson-rumped Waxbill
- Crimson Rosella
- Croaking Cisticola
- Crowned Eagle
- Crowned Hornbill
- Crowned Lapwing
- Curl-crested Jay
- Curlew Sandpiper
- Cut-throat Finch