| Name | Other Name | Family | Nativ Name | ISO6391 Code | ISO6392T Code | ISO6392B Code | ISO6393 Code | Notes |
|---|---|---|---|---|---|---|---|---|
| Corsican | Indo-European | corsu; lingua corsa | co | cos | cos | cos | ||
| Cornish | Indo-European | Kernewek | kw | cor | cor | cor | ||
| Chuvash | Turkic | чӑваш чӗлхи | cv | chv | chv | chv | ||
| Church Slavic | Church Slavonic;Old Church Slavonic;Old Slavonic;Old Bulgarian | Indo-European | ѩзыкъ словѣньскъ | cu | chu | chu | chu | ancient; in use by Orthodox Church |
| Chinese | Sino-Tibetan | 中文 (Zhōngwén); 汉语; 漢語 | zh | zho | chi | zho + 13 | macrolanguage | |
| Chichewa | Chewa;Nyanja | Niger–Congo | chiCheŵa; chinyanja | ny | nya | nya | nya | |
| Chechen | Northeast Caucasian | нохчийн мотт | ce | che | che | che | ||
| Chamorro | Austronesian | Chamoru | ch | cha | cha | cha | ||
| Central Khmer | Austroasiatic | ខ្មែរ; ខេមរភាសា; ភាសាខ្មែរ | km | khm | khm | khm | also known as Khmer or Cambodian | |
| Catalan | Valencian | Indo-European | català; valencià | ca | cat | cat | cat |