- California Quail
- Cape Barren Goose
- Cape Gannet
- Cape Petrel
- Cape White-eye
- Carmelite Sunbird
- Cassin's Flycatcher
- Cassin's Spinetail
- Cattle Tyrant
- Chattering Cisticola
- Chestnut-breasted Nigrita
- Chestnut-capped Flycatcher
- Chestnut-eared Aracari
- Chestnut Teal
- Chestnut Wattle-eye
- Cinereous Vulture
- Coconut Lorikeet
- Collared Flycatcher
- Collared Pratincole
- Collared Sunbird
- Common Blackbird
- Common Bulbul
- Common Buzzard
- Common Chiffchaff (tristis)
- Common Diving Petrel
- Common Eider
- Common Greenshank
- Common Linnet
- Common Murre
- Common Myna
- Common Rock Thrush
- Common Rosefinch
- Common Tern
- Compact Weaver
- Congo Pied Hornbill
- Copper Sunbird
- Corn Bunting
- Corn Crake
- Corsican Finch
- Cory's Shearwater
- Crimson Rosella
- Crowned Eagle
- Crozet Shag