word | | Country name |
| conventional | Mauritius | conventional long form: Republic of Mauritius conventional short form: Mauritius local long form: Republic of Mauritius local short form: Mauritius |
| conventional | Mayotte | conventional long form: Department Collectivity of Mayotte conventional short form: Mayotte |
| conventional | Mexico | conventional long form: United Mexican States conventional short form: Mexico local long form: Estados Unidos Mexicanos local short form: Mexico |
| conventional | Micronesia, Federated States of | conventional long form: Federated States of Micronesia conventional short form: none local long form: Federated States of Micronesia local short form: none former: Trust Territory of the Pacific Islands, Ponape, Truk, and ... |
| conventional | Moldova | conventional long form: Republic of Moldova conventional short form: Moldova local long form: Republica Moldova local short form: Moldova former: Moldavian Soviet Socialist Republic, Moldovan Soviet Socialist Republic |
| conventional | Monaco | conventional long form: Principality of Monaco conventional short form: Monaco local long form: Principaute de Monaco local short form: Monaco |
| conventional | Mongolia | conventional long form: none conventional short form: Mongolia local long form: none local short form: Mongol Uls former: Outer Mongolia |
| conventional | Montenegro | conventional long form: none conventional short form: Montenegro local long form: none local short form: Crna Gora former: People's Republic of Montenegro, Socialist Republic of Montenegro, Republic of Montenegro |
| conventional | Montserrat | conventional long form: none conventional short form: Montserrat |
| conventional | Morocco | conventional long form: Kingdom of Morocco conventional short form: Morocco local long form: Al Mamlakah al Maghribiyah local short form: Al Maghrib |