- Caatinga Antwren
- Caatinga Cacholote
- Caatinga Parakeet
- Cachar Wedge-billed Babbler
- California Gnatcatcher
- California Thrasher
- California Towhee
- Campbell Albatross
- Campbell Shag
- Campina Thrush
- Campo Troupial
- Canary Islands Chiffchaff
- Canivet's Emerald
- Canyon Canastero
- Canyon Wren
- Cape Bunting
- Cape Clapper Lark
- Cape Sparrow
- Cape Verde Buzzard
- Cape Verde Swift
- Cape Verde Warbler
- Capuchin Babbler
- Carbonated Sierra Finch
- Carmelite Sunbird
- Carmiol's Tanager
- Carruthers's Cisticola
- Carunculated Fruit Dove
- Caspian Plover
- Cassin's Finch
- Cassin's Flycatcher
- Cassin's Hawk-Eagle
- Cassin's Spinetail
- Cassin's Vireo
- Cauca Guan
- Caura Antbird
- Cave Swiftlet
- Ceara Gnateater
- Ceara Woodcreeper
- Chachapoyas Antpitta
- Chaco Earthcreeper
- Chapada Flycatcher
- Chapin's Apalis
- Chaplin's Barbet
- Chapman's Antshrike
- Chattering Cisticola
- Checker-throated Woodpecker
- Checkered Woodpecker
- Cheer Pheasant
- Cherrie's Antwren
- Cherry-throated Tanager
- Chestnut-backed Antbird
- Chestnut-backed Antshrike
- Chestnut-backed Tanager
- Chestnut-backed Thornbird
- Chestnut-banded Plover
- Chestnut-bellied Cotinga
- Chestnut-bellied Euphonia
- Chestnut-bellied Flowerpiercer
- Chestnut-bellied Sandgrouse
- Chestnut-bellied Starling
- Chestnut-bellied Thrush
- Chestnut-bellied Tit
- Chestnut-belted Gnateater
- Chestnut-breasted Coronet
- Chestnut-breasted Cuckoo
- Chestnut-breasted Mountain Finch
- Chestnut-breasted Nigrita
- Chestnut-breasted Wren
- Chestnut-capped Blackbird
- Chestnut-capped Brushfinch
- Chestnut-capped Warbler
- Chestnut-colored Woodpecker
- Chestnut-crested Antbird
- Chestnut-crested Yuhina
- Chestnut-crowned Antpitta
- Chestnut-crowned Becard
- Chestnut-crowned Foliage-gleaner
- Chestnut-eared Bunting
- Chestnut-fronted Macaw
- Chestnut-headed Bee-eater
- Chestnut-headed Crake
- Chestnut-headed Sparrow-Lark
- Chestnut-headed Tanager
- Chestnut-headed Tesia
- Chestnut-hooded Laughingthrush
- Chestnut-naped Forktail
- Chestnut-rumped Babbler
- Chestnut-shouldered Antwren
- Chestnut-tailed Starling
- Chestnut-throated Seedeater
- Chestnut-throated Spinetail
- Chestnut Munia
- Chestnut Piculet
- Chestnut Wattle-eye
- Chestnut Wood Quail
- Chico's Tyrannulet
- Chilean Flamingo
- Chinese Beautiful Rosefinch
- Chinspot Batis
- Chiriqui Foliage-gleaner
- Chiriqui Quail-Dove
- Choco Elaenia
- Choco Manakin
- Choco Screech Owl
- Choco Tapaculo
- Chotoy Spinetail
- Chowchilla
- Chubb's Cisticola
- Chucao Tapaculo
- Chukar Partridge
- Churring Cisticola
- Cinereous Finch
- Cinereous Harrier
- Cinereous Mourner
- Cinereous Tinamou
- Cinereous Warbling Finch
- Cinnamon-bellied Ground Tyrant
- Cinnamon-breasted Tody-Tyrant
- Cinnamon-chested Bee-eater
- Cinnamon-crested Spadebill
- Cinnamon-faced Tyrannulet
- Cinnamon-rumped Foliage-gleaner
- Cinnamon-rumped Seedeater
- Cinnamon-tailed Sparrow
- Cinnamon-throated Hermit
- Cinnamon-throated Woodcreeper
- Cinnamon Bracken Warbler
- Cinnamon Flycatcher
- Cinnamon Hummingbird
- Cinnamon Neopipo
- Cinnamon Screech Owl
- Cinnamon Warbling Finch
- Citrine Wagtail
- Citrine Warbler
- Citron-bellied Attila
- Clapper Rail
- Claret-breasted Fruit Dove
- Clarke's Weaver
- Clay-colored Thrush
- Cloud-forest Pygmy Owl
- Cloud Cisticola
- Coal-crested Finch
- Coal Tit
- Cobb's Wren
- Cocha Antshrike
- Cockatiel
- Cocoa Thrush
- Cocoi Heron
- Colima Pygmy Owl
- Colima Warbler
- Collared Bush Robin
- Collared Crescentchest
- Collared Gnatwren
- Collared Grosbeak
- Collared Nightjar
- Collared Owlet
- Collared Palm Thrush
- Collared Puffbird
- Collared Trogon
- Collared Warbling Finch
- Common Chlorospingus
- Common Cicadabird
- Common Diving Petrel
- Common Emerald Dove
- Common Ground Dove
- Common Jery
- Common Newtonia
- Common Paradise Kingfisher
- Common Rock Thrush
- Common Scale-backed Antbird
- Common Sunbird-Asity
- Compact Weaver
- Cone-billed Tanager
- Coopmans's Tyrannulet
- Copper-tailed Hummingbird
- Copper Sunbird
- Coppery-chested Jacamar
- Coppery-headed Emerald
- Coppery-tailed Coucal
- Coppery Emerald
- Coppery Metaltail
- Coqui Francolin
- Cory's Shearwater
- Coscoroba Swan
- Couch's Kingbird
- Cozumel Emerald
- Crane Hawk
- Cream-colored Courser
- Cream-colored Woodpecker
- Cream-eyed Bulbul
- Cream-striped Bulbul
- Cream-throated White-eye
- Cream-vented Bulbul
- Creamy-crested Spinetail
- Crescent-chested Puffbird
- Crescent-chested Warbler
- Crescent-faced Antpitta
- Crested Auklet
- Crested Bobwhite
- Crested Caracara
- Crested Doradito
- Crested Drongo
- Crested Duck
- Crested Francolin
- Crested Gallito
- Crested Jayshrike
- Crested Oropendola
- Crested Partridge
- Crested Pigeon
- Crested Quetzal
- Crested Serpent Eagle
- Crestless Curassow
- Cricket Warbler
- Crimson-browed Finch
- Crimson-collared Grosbeak
- Crimson-headed Partridge
- Crimson-hooded Manakin
- Crimson-mantled Woodpecker
- Crimson-rumped Toucanet
- Crimson-rumped Waxbill
- Crimson-winged Woodpecker
- Crimson Fruitcrow
- Crimson Seedcracker
- Croaking Cisticola
- Croaking Ground Dove
- Crossley's Vanga
- Crowned Chat-Tyrant
- Crowned Eagle
- Cryptic Forest Falcon
- Cuckoo-roller
- Cundinamarca Antpitta
- Curl-crested Aracari
- Curve-billed Reedhaunter
- Curve-billed Scythebill
- Curve-winged Sabrewing (excellens)
- Cuzco Brushfinch
- Cuzco Warbler
- Cyprus Scops Owl
- Cyprus Wheatear