| Country | Legal system |
| Heard Island and McDonald Islands | the laws of Australia, where applicable, apply |
| Holy See (Vatican City) | religious legal system based on canon (religious) law |
| Honduras | civil law system |
| Hong Kong | mixed legal system of common law based on the English model and Chinese customary law (in matters of family and land tenure) |
| Hungary | civil legal system influenced by the German model |
| Iceland | civil law system influenced by the Danish model |
| India | common law system based on the English model; separate personal law codes apply to Muslims, Christians, and Hindus; judicial review of legislative acts |
| Indian Ocean | void |
| Indonesia | civil law system based on the Roman-Dutch model and influenced by customary law |
| Iran | religious legal system based on sharia law |
| Iraq | mixed legal system of civil and Islamic law |
| Ireland | common law system based on the English model but substantially modified by customary law; judicial review of legislative acts in Supreme Court |
| Isle of Man | the laws of the UK where applicable apply and include Manx statutes |
| Israel | mixed legal system of English common law, British Mandate regulations, and Jewish, Christian, and Muslim religious laws |
| Italy | civil law system; judicial review under certain conditions in Constitutional Court |
| Jamaica | common law system based on the English model |
| Jan Mayen | the laws of Norway, where applicable, apply |
| Japan | civil law system based on German model; system also reflects Anglo-American influence and Japanese traditions; judicial review of legislative acts in the Supreme Court |
| Jersey | the laws of the UK, where applicable, apply; local statutes |
| Jordan | mixed legal system of civil law and Islamic religious law; judicial review of legislative acts in a specially provided High Tribunal |