word | | Country name |
| Yemen | Yemen | conventional long form: Republic of Yemen conventional short form: Yemen local long form: Al Jumhuriyah al Yamaniyah local short form: Al Yaman former: Yemen Arab Republic [Yemen (Sanaa) or North Yemen] and ... |
| Yisra | Israel | conventional long form: State of Israel conventional short form: Israel local long form: Medinat Yisra'el local short form: Yisra'el |
| Yugoslav | Macedonia | ... short form: Makedonija note: the provisional designation used by the UN, EU, and NATO is the "former Yugoslav Republic of Macedonia" (FYROM) former: People's Republic of Macedonia, Socialist Republic of Macedonia |
| Yul | Bhutan | conventional long form: Kingdom of Bhutan conventional short form: Bhutan local long form: Druk Gyalkhap local short form: Druk Yul |
| yun | Armenia | conventional long form: Republic of Armenia conventional short form: Armenia local long form: Hayastani Hanrapetut'yun local short form: Hayastan former: Armenian Soviet Socialist Republic, Armenian Republic |
| Zaire | Congo, Democratic Republic of the | ... Republic of the Congo conventional short form: DRC local long form: Republique Democratique du Congo local short form: RDC former: Congo Free State, Belgian Congo, Congo/Leopoldville, Congo/Kinshasa, Zaire abbreviation: DRC |
| Zambia | Zambia | conventional long form: Republic of Zambia conventional short form: Zambia former: Northern Rhodesia |
| Zanzibar | Tanzania | conventional long form: United Republic of Tanzania conventional short form: Tanzania local long form: Jamhuri ya Muungano wa Tanzania local short form: Tanzania former: United Republic of Tanganyika and Zanzibar |
| Zhongguo | China | conventional long form: People's Republic of China conventional short form: China local long form: Zhonghua Renmin Gongheguo local short form: Zhongguo abbreviation: PRC |
| Zhonghua | China | conventional long form: People's Republic of China conventional short form: China local long form: Zhonghua Renmin Gongheguo local short form: Zhongguo abbreviation: PRC |