word | | Country name |
| Jaza | Algeria | conventional long form: People's Democratic Republic of Algeria conventional short form: Algeria local long form: Al Jumhuriyah al Jaza'iriyah ad Dimuqratiyah ash Sha'biyah local short form: Al Jaza'ir |
| Jersey | Jersey | conventional long form: Bailiwick of Jersey conventional short form: Jersey |
| Jibuti | Djibouti | ... long form: Republic of Djibouti conventional short form: Djibouti local long form: Republique de Djibouti/Jumhuriyat Jibuti local short form: Djibouti/Jibuti former: French Territory of the Afars and Issas, French Somaliland |
| Johnston | United States Pacific Island Wildlife Refuges | conventional long form: none conventional short form: Baker Island; Howland Island; Jarvis Island; Johnston Atoll; Kingman Reef; Midway Islands; Palmyra Atoll |
| Jomhuri | Afghanistan | conventional long form: Islamic Republic of Afghanistan conventional short form: Afghanistan local long form: Jomhuri-ye Eslami-ye Afghanestan local short form: Afghanestan former: Republic of Afghanistan |
| Jomhuri | Iran | conventional long form: Islamic Republic of Iran conventional short form: Iran local long form: Jomhuri-ye Eslami-ye Iran local short form: Iran former: Persia |
| Jordan | Jordan | conventional long form: Hashemite Kingdom of Jordan conventional short form: Jordan local long form: Al Mamlakah al Urduniyah al Hashimiyah local short form: Al Urdun former: Transjordan |
| Jumhooriyyaa | Maldives | conventional long form: Republic of Maldives conventional short form: Maldives local long form: Dhivehi Raajjeyge Jumhooriyyaa local short form: Dhivehi Raajje |
| Jumhurii | Tajikistan | conventional long form: Republic of Tajikistan conventional short form: Tajikistan local long form: Jumhurii Tojikiston local short form: Tojikiston former: Tajik Soviet Socialist Republic |
| Jumhuriyah | Algeria | conventional long form: People's Democratic Republic of Algeria conventional short form: Algeria local long form: Al Jumhuriyah al Jaza'iriyah ad Dimuqratiyah ash Sha'biyah local short form: Al Jaza'ir |
| Jumhuriyah | Lebanon | conventional long form: Lebanese Republic conventional short form: Lebanon local long form: Al Jumhuriyah al Lubnaniyah local short form: Lubnan former: Greater Lebanon |