Christmas Island [Indian Ocean] — Australia
Christmas Island [Pacific Ocean] — Kiribati (Kiritimati)
Chukchi Sea — Arctic Ocean
Ciskei — South Africa
Ciudad Juarez [US Consulate General] — Mexico
Cluj-Napoca [US Branch Office] — Romania
Coco, Isla del — Costa Rica
Cocos Islands — Cocos (Keeling) Islands
Colombo [US Embassy] — Sri Lanka
Colon, Archipielago de — Ecuador (Galapagos Islands)