| Name | Other Name | Family | Nativ Name | ISO6391 Code | ISO6392T Code | ISO6392B Code | ISO6393 Code | Notes |
|---|---|---|---|---|---|---|---|---|
| Inupiaq | Eskimo–Aleut | Iñupiaq; Iñupiatun | ik | ipk | ipk | ipk + 2 | macrolanguage | |
| Ido | Constructed | Ido | io | ido | ido | ido | constructed by De Beaufront; 1907; as variation of Esperanto | |
| Icelandic | Indo-European | Íslenska | is | isl | ice | isl | ||
| Italian | Indo-European | Italiano | it | ita | ita | ita | ||
| Inuktitut | Eskimo–Aleut | ᐃᓄᒃᑎᑐᑦ | iu | iku | iku | iku + 2 | macrolanguage | |
| Japanese | Japonic | 日本語 (にほんご) | ja | jpn | jpn | jpn | ||
| Javanese | Austronesian | ꦧꦱꦗꦮ; Basa Jawa | jv | jav | jav | jav | ||
| Georgian | South Caucasian | ქართული | ka | kat | geo | kat | ||
| Kongo | Niger–Congo | Kikongo | kg | kon | kon | kon + 3 | macrolanguage | |
| Kikuyu | Gikuyu | Niger–Congo | Gĩkũyũ | ki | kik | kik | kik |