word | | Nationality |
| adjective | Japan | noun: Japanese (singular and plural) adjective: Japanese |
| adjective | Jersey | noun: Channel Islander(s) adjective: Channel Islander |
| adjective | Jordan | noun: Jordanian(s) adjective: Jordanian |
| adjective | Kazakhstan | noun: Kazakhstani(s) adjective: Kazakhstani |
| adjective | Kenya | noun: Kenyan(s) adjective: Kenyan |
| adjective | Kiribati | noun: I-Kiribati (singular and plural) adjective: I-Kiribati |
| adjective | Korea, North | noun: Korean(s) adjective: Korean |
| adjective | Korea, South | noun: Korean(s) adjective: Korean |
| adjective | Kosovo | noun: Kosovar (Albanian), Kosovac (Serbian) adjective: Kosovar (Albanian), Kosovski (Serbian) note: Kosovan, a neutral term, is sometimes also used as a noun or adjective |
| adjective | Kuwait | noun: Kuwaiti(s) adjective: Kuwaiti |
| adjective | Kyrgyzstan | noun: Kyrgyzstani(s) adjective: Kyrgyzstani |
| adjective | Laos | noun: Lao(s) or Laotian(s) adjective: Lao or Laotian |
| adjective | Latvia | noun: Latvian(s) adjective: Latvian |
| adjective | Lebanon | noun: Lebanese (singular and plural) adjective: Lebanese |
| adjective | Lesotho | noun: Mosotho (singular), Basotho (plural) adjective: Basotho |
| adjective | Liberia | noun: Liberian(s) adjective: Liberian |
| adjective | Libya | noun: Libyan(s) adjective: Libyan |