| Country | Geography - note |
| Lithuania | fertile central plains are separated by hilly uplands that are ancient glacial deposits |
| Luxembourg | landlocked; the only Grand Duchy in the world |
| Macau | essentially urban; an area of land reclaimed from the sea measuring 5.2 sq km and known as Cotai now connects the islands of Coloane and Taipa; the island area is connected to the mainland peninsula by three bridges |
| Macedonia | landlocked; major transportation corridor from Western and Central Europe to Aegean Sea and Southern Europe to Western Europe |
| Madagascar | world's fourth-largest island; strategic location along Mozambique Channel |
| Malawi | landlocked; Lake Nyasa, some 580 km long, is the country's most prominent physical feature |
| Malaysia | strategic location along Strait of Malacca and southern South China Sea |
| Maldives | 1,190 coral islands grouped into 26 atolls (200 inhabited islands, plus 80 islands with tourist resorts); archipelago with strategic location astride and along major sea lanes in Indian Ocean |
| Mali | landlocked; divided into three natural zones: the southern, cultivated Sudanese; the central, semiarid Sahelian; and the northern, arid Saharan |
| Malta | the country comprises an archipelago, with only the three largest islands (Malta, Ghawdex or Gozo, and Kemmuna or Comino) being inhabited; numerous bays provide good harbors; Malta and Tunisia are discussing the commercial exploitation of the continental shelf between their countries, particularly for oil exploration |
| Marshall Islands | the islands of Bikini and Enewetak are former US nuclear test sites; Kwajalein atoll, famous as a World War II battleground, surrounds the world's largest lagoon and is used as a US missile test range; the island city of Ebeye is the second largest settlement in the Marshall Islands, after the capital of Majuro, and one of the most densely populated locations in the Pacific |
| Mauritania | most of the population is concentrated in the cities of Nouakchott and Nouadhibou and along the Senegal River in the southern part of the country |
| Mauritius | the main island, from which the country derives its name, is of volcanic origin and is almost entirely surrounded by coral reefs; home of the dodo, a large flightless bird related to pigeons, driven to extinction by the end of the 17th century through a combination of hunting and the introduction of predatory species |
| Mayotte | part of Comoro Archipelago (18 islands) |
| Mexico | strategic location on southern border of US; corn (maize), one of the world's major grain crops, is thought to have originated in Mexico |
| Micronesia, Federated States of | four major island groups totaling 607 islands |
| Moldova | landlocked; well endowed with various sedimentary rocks and minerals including sand, gravel, gypsum, and limestone |
| Monaco | second-smallest independent state in the world (after Holy See); almost entirely urban |
| Mongolia | landlocked; strategic location between China and Russia |
| Montenegro | strategic location along the Adriatic coast |
| Montserrat | the island is entirely volcanic in origin and comprised of three major volcanic centers of differing ages |
| Morocco | strategic location along Strait of Gibraltar |
| Mozambique | the Zambezi flows through the north-central and most fertile part of the country |
| Namibia | first country in the world to incorporate the protection of the environment into its constitution; some 14% of the land is protected, including virtually the entire Namib Desert coastal strip |
| Nauru | Nauru is one of the three great phosphate rock islands in the Pacific Ocean - the others are Banaba (Ocean Island) in Kiribati and Makatea in French Polynesia; only 53 km south of Equator |