| Country | Legal system |
| Holy See (Vatican City) | based on Code of Canon Law and revisions to it |
| Honduras | rooted in Roman and Spanish civil law with increasing influence of English common law; recent judicial reforms include abandoning Napoleonic legal codes in favor of the oral adversarial system; accepts ICJ jurisdiction with reservations |
| Hong Kong | based on English common law |
| Howland Island | void |
| Hungary | based on the German-Austrian legal system; accepts compulsory ICJ jurisdiction with reservations |
| Iceland | civil law system based on Danish law; has not accepted compulsory ICJ jurisdiction |
| Iles Eparses | void |
| India | based on English common law; judicial review of legislative acts; accepts compulsory ICJ jurisdiction with reservations; separate personal law codes apply to Muslims, Christians, and Hindus |
| Indian Ocean | void |
| Indonesia | based on Roman-Dutch law, substantially modified by indigenous concepts and by new criminal procedures and election codes; has not accepted compulsory ICJ jurisdiction |
| Iran | based on Sharia law system; has not accepted compulsory ICJ jurisdiction |
| Iraq | based on European civil and Islamic law under the framework outlined in the Iraqi Constitution; has not accepted compulsory ICJ jurisdiction |
| Ireland | based on English common law, substantially modified by indigenous concepts; judicial review of legislative acts in Supreme Court; has not accepted compulsory ICJ jurisdiction |
| Isle of Man | the laws of the UK, where applicable, apply and Manx statutes |
| Israel | mixture of English common law, British Mandate regulations, and, in personal matters, Jewish, Christian, and Muslim legal systems; in December 1985, Israel informed the UN Secretariat that it would no longer accept compulsory ICJ jurisdiction |
| Italy | based on civil law system; appeals treated as new trials; judicial review under certain conditions in Constitutional Court; has not accepted compulsory ICJ jurisdiction |
| Jamaica | based on English common law; has not accepted compulsory ICJ jurisdiction |
| Jan Mayen | the laws of Norway, where applicable, apply |
| Japan | modeled after German civil law system with English-American influence; judicial review of legislative acts in the Supreme Court; accepts compulsory ICJ jurisdiction with reservations |
| Jarvis Island | void |
| Jersey | the laws of the UK, where applicable, apply and local statutes; justice is administered by the Royal Court |
| Johnston Atoll | void |
| Jordan | based on Islamic law and French codes; judicial review of legislative acts in a specially provided High Tribunal; has not accepted compulsory ICJ jurisdiction |
| Juan de Nova Island | void |
| Kazakhstan | based on Islamic law and Roman law; has not accepted compulsory ICJ jurisdiction |
| Kenya | based on Kenyan statutory law, Kenyan and English common law, tribal law, and Islamic law; judicial review in High Court; accepts compulsory ICJ jurisdiction with reservations; constitutional amendment of 1982 making Kenya a de jure one-party state repealed in 1991 |
| Kingman Reef | void |
| Kiribati | NA |
| Korea, North | based on Prussian civil law system with Japanese influences and Communist legal theory; no judicial review of legislative acts; has not accepted compulsory ICJ jurisdiction |
| Korea, South | combines elements of continental European civil law systems, Anglo-American law, and Chinese classical thought; has not accepted compulsory ICJ jurisdiction |
| Kosovo | evolving legal system based on terms of UN Special Envoy Martti AHTISAARI's Plan for Kosovo's supervised independence |