- Caatinga Cacholote
- Caatinga Parakeet
- Cabot's Tern
- Cactus Wren
- California Gull
- California Quail
- California Thrasher
- California Towhee
- Calliope Hummingbird
- Campo Flicker
- Campo Troupial
- Canada Goose
- Canada Jay
- Canada Warbler
- Canvasback
- Canyon Towhee
- Canyon Wren
- Cape Batis
- Cape May Warbler
- Cape Parrot
- Capped Conebill
- Capped Heron
- Capped White-eye
- Carib Grackle
- Caribbean Elaenia
- Caribbean Martin
- Carolina Wren
- Carunculated Caracara
- Caspian Gull
- Caspian Tern
- Cassin's Finch
- Cassin's Kingbird
- Cattle Tyrant
- Cedar Waxwing
- Chaco Chachalaca
- Chaco Earthcreeper
- Chaco Sparrow
- Chalk-browed Mockingbird
- Channel-billed Toucan
- Channel-billed Toucan (ariel)
- Checker-throated Woodpecker
- Chestnut-backed Antbird
- Chestnut-backed Chickadee
- Chestnut-bellied Euphonia
- Chestnut-bellied Fantail
- Chestnut-bellied Guan
- Chestnut-bellied Nuthatch
- Chestnut-bellied Seed Finch
- Chestnut-bellied Seedeater
- Chestnut-bellied Thrush
- Chestnut-breasted Coronet
- Chestnut-breasted Malkoha
- Chestnut-breasted Mannikin
- Chestnut-capped Blackbird
- Chestnut-capped Laughingthrush
- Chestnut-capped Puffbird
- Chestnut-capped Warbler
- Chestnut-crowned Antpitta
- Chestnut-crowned Becard
- Chestnut-eared Aracari
- Chestnut-faced Babbler
- Chestnut-fronted Macaw
- Chestnut-headed Bee-eater
- Chestnut-headed Oropendola
- Chestnut-naped Forktail
- Chestnut-sided Warbler
- Chestnut-throated Monal-Partridge
- Chestnut-throated Seedeater
- Chestnut-tipped Toucanet
- Chestnut-vented Nuthatch
- Chestnut-winged Babbler
- Chestnut Thrush
- Chestnut Wattle-eye
- Chiguanco Thrush
- Chilean Elaenia
- Chilean Flamingo
- Chilean Mockingbird
- Chilean Pigeon
- Chilean Seaside Cinclodes
- Chilean Skua
- Chilean Swallow
- Chilean Woodstar
- Chiloe Wigeon
- Chimango Caracara
- Chinese Egret
- Chinese Grouse
- Chinese Leaf Warbler
- Chinese Nuthatch
- Chinese Penduline Tit
- Chinese Pond Heron
- Chinspot Batis
- Chinstrap Penguin
- Chipping Sparrow
- Choco Trogon
- Chopi Blackbird
- Chotoy Spinetail
- Chucao Tapaculo
- Cinereous Becard
- Cinereous Conebill
- Cinereous Ground Tyrant
- Cinereous Harrier
- Cinereous Tit
- Cinereous Tyrant
- Cinereous Warbling Finch
- Cinnamon-bellied Flowerpiercer
- Cinnamon-bellied Ground Tyrant
- Cinnamon-rumped Seedeater
- Cinnamon-rumped Trogon
- Cinnamon-vented Piha
- Cinnamon Flycatcher
- Cinnamon Hummingbird
- Cinnamon Tanager
- Cinnamon Teal
- Citreoline Trogon
- Citrine Wagtail
- Citron-headed Yellow Finch
- Clark's Grebe
- Clay-colored Sparrow
- Clay-colored Thrush
- Cliff Flycatcher
- Club-winged Manakin
- Coal Tit
- Cobalt-rumped Parrotlet
- Cobalt-winged Parakeet
- Cocoa Thrush
- Cocoi Heron
- Coconut Lorikeet
- Coleto
- Collared Antshrike
- Collared Aracari
- Collared Inca
- Collared Kingfisher
- Collared Owlet
- Collared Plover
- Collared Sunbird
- Collared Trogon
- Collared Whitestart
- Comb-crested Jacana
- Common Black Hawk
- Common Blackbird
- Common Buzzard
- Common Cactus Finch
- Common Chiffchaff
- Common Chlorospingus (ophthalmicus)
- Common Eider
- Common Flameback
- Common Goldeneye
- Common Grackle
- Common Ground Dove
- Common Gull
- Common Hill Myna
- Common Iora
- Common Kingfisher
- Common Loon
- Common Merganser
- Common Moorhen
- Common Murre
- Common Myna
- Common Nighthawk
- Common Paradise Kingfisher
- Common Pheasant
- Common Potoo
- Common Redshank
- Common Reed Bunting
- Common Rosefinch
- Common Scale-backed Antbird
- Common Smoky Honeyeater
- Common Starling
- Common Tailorbird
- Common Tern
- Common Tody-Flycatcher
- Common Wood Pigeon
- Common Yellowthroat
- Congo Pied Hornbill
- Copper-tailed Starling
- Coppersmith Barbet
- Coppery-chested Jacamar
- Coppery-headed Emerald
- Cordilleran Canastero
- Cordoba Cinclodes
- Correndera Pipit
- Coscoroba Swan
- Costa's Hummingbird
- Couch's Kingbird
- Crag Chilia
- Cream-backed Woodpecker
- Cream-colored Woodpecker
- Creamy-bellied Thrush
- Crescent-chested Warbler
- Crested Auklet
- Crested Black Tyrant
- Crested Bunting
- Crested Caracara
- Crested Duck
- Crested Gallito
- Crested Goshawk
- Crested Guan
- Crested Hornero
- Crested Myna
- Crested Oropendola
- Crested Quetzal
- Crested Serpent Eagle
- Crested Tit-warbler
- Crimson-backed Tanager
- Crimson-breasted Finch
- Crimson-breasted Flowerpecker
- Crimson-collared Tanager
- Crimson-crested Woodpecker
- Crimson-hooded Manakin
- Crimson-mantled Woodpecker
- Crimson-rumped Toucanet
- Crimson-rumped Waxbill
- Crimson-winged Woodpecker
- Crimson Sunbird
- Crinkle-collared Manucode
- Crissal Thrasher
- Croaking Cisticola
- Croaking Ground Dove
- Crowned Slaty Flycatcher
- Crowned Woodnymph
- Cuban Black Hawk
- Cuban Blackbird
- Cuban Bullfinch
- Cuban Crow
- Cuban Emerald
- Cuban Gnatcatcher
- Cuban Green Woodpecker
- Cuban Oriole
- Cuban Pewee
- Cuban Pygmy Owl
- Cuban Solitaire
- Cuban Tody
- Cuban Trogon
- Cuban Vireo
- Curve-billed Thrasher
- Cuzco Warbler