| Country | Legal system |
| Madagascar | civil law system based on the old French civil code and customary law in matters of marriage, family, and obligation |
| Malawi | mixed legal system of English common law and customary law; judicial review of legislative acts in the Supreme Court of Appeal |
| Malaysia | mixed legal system of English common law, Islamic law, and customary law; judicial review of legislative acts in the Supreme Court at request of supreme head of the federation |
| Maldives | Islamic religious legal system with English common law influences, primarily in commercial matters |
| Mali | civil law system based on the French civil law model and influenced by customary law; judicial review of legislative acts in Constitutional Court |
| Malta | mixed legal system of English common law and civil law (based on the Roman and Napoleonic civil codes) |
| Marshall Islands | mixed legal system of US and English common law, customary law, and local statutes |
| Mauritania | mixed legal system of Islamic and French civil law |
| Mauritius | civil legal system based on French civil law with some elements of English common law |
| Mayotte | the laws of France where applicable apply |
| Mexico | civil law system with US constitutional law theory influence; judicial review of legislative acts |
| Micronesia, Federated States of | mixed legal system of common and customary law |
| Moldova | civil law system with Germanic law influences; Constitutional Court review of legislative acts |
| Monaco | civil law system influenced by French legal tradition |
| Mongolia | civil law system influenced by Soviet and Romano-Germanic legal systems; constitution ambiguous on judicial review of legislative acts |
| Montenegro | civil law |
| Montserrat | English common law |
| Morocco | mixed legal system of civil law based on French law and Islamic law; judicial review of legislative acts by Supreme Court |