- Cactus Canastero
- Calandra Lark
- California Gull
- Campo Flicker
- Cape Bunting
- Cape Cormorant
- Cape Crow
- Cape Rock Thrush
- Cape Sparrow
- Cape Starling
- Cape Teal
- Cape Vulture
- Cape Wagtail
- Cape White-eye
- Capped Conebill
- Carunculated Caracara
- Caspian Gull
- Caspian Tern
- Cattle Tyrant
- Chaco Earthcreeper
- Chaco Puffbird
- Chalk-browed Mockingbird
- Chestnut-banded Plover
- Chestnut-bellied Euphonia
- Chestnut-breasted Coronet
- Chestnut-breasted Mountain Finch
- Chestnut-capped Brushfinch
- Chestnut-capped Puffbird
- Chestnut-crowned Antpitta
- Chestnut-crowned Becard
- Chestnut-eared Aracari
- Chestnut-flanked White-eye
- Chestnut-fronted Macaw
- Chestnut-sided Warbler
- Chestnut-throated Seedeater
- Chestnut-vented Warbler
- Chestnut-winged Cinclodes
- Chestnut Munia
- Chestnut Woodpecker
- Chiguanco Thrush
- Chilean Flamingo
- Chimango Caracara
- Chinese Bamboo Partridge
- Chinese Grosbeak
- Chinese Hwamei
- Chinese Leaf Warbler
- Chinese Pond Heron
- Chinspot Batis
- Cinereous Bunting
- Cinereous Conebill
- Cinereous Ground Tyrant
- Cinereous Tyrant
- Cinereous Vulture
- Cinnamon-throated Woodcreeper
- Cinnamon Attila
- Cinnamon Becard
- Cinnamon Flycatcher
- Cinnamon Teal
- Citrine Wagtail
- Citrine Warbler
- Claudia's Leaf Warbler
- Clay-colored Thrush
- Cliff Flycatcher
- Club-winged Manakin
- Coastal Miner
- Cobalt-winged Parakeet
- Cocoi Heron
- Collared Aracari
- Collared Finchbill
- Collared Flycatcher
- Collared Inca
- Collared Kingfisher
- Collared Plover
- Collared Pratincole
- Collared Sunbird
- Collared Trogon
- Collared Warbling Finch
- Collared Whitestart
- Common Black Hawk
- Common Blackbird
- Common Bulbul
- Common Cuckoo
- Common Gallinule
- Common Greenshank
- Common Hawk-Cuckoo
- Common Hill Myna
- Common Iora
- Common Kestrel
- Common Kingfisher
- Common Myna
- Common Ostrich
- Common Pheasant
- Common Potoo
- Common Rock Thrush
- Common Rosefinch
- Common Scale-backed Antbird
- Common Scimitarbill
- Common Shelduck
- Common Tailorbird
- Common Tody-Flycatcher
- Coppersmith Barbet
- Coppery-headed Emerald
- Coqui Francolin
- Cordoba Cinclodes
- Coscoroba Swan
- Cream-colored Courser
- Cream-winged Cinclodes
- Creamy-bellied Thrush
- Crescent-chested Puffbird
- Crested Barbet
- Crested Duck
- Crested Francolin
- Crested Goshawk
- Crested Guan
- Crested Honey Buzzard
- Crested Hornero
- Crested Myna
- Crested Serpent Eagle
- Cretzschmar's Bunting
- Crimson-backed Sunbird
- Crimson-breasted Shrike
- Crimson-mantled Woodpecker
- Crimson-rumped Toucanet
- Crimson Sunbird
- Croaking Ground Dove
- Crowned Chat-Tyrant
- Crowned Cormorant
- Crowned Hornbill
- Crowned Lapwing
- Crowned Slaty Flycatcher
- Crowned Woodnymph
- Curlew Sandpiper