| Country | Legal system |
| Tokelau | New Zealand and local statutes |
| Tonga | based on English common law; has not accepted compulsory ICJ jurisdiction |
| Trinidad and Tobago | based on English common law; judicial review of legislative acts in the Supreme Court; has not accepted compulsory ICJ jurisdiction |
| Tunisia | based on French civil law system and Islamic law; some judicial review of legislative acts in the Supreme Court in joint session; has not accepted compulsory ICJ jurisdiction |
| Turkey | civil law system derived from various European continental legal systems; note - member of the European Court of Human Rights (ECHR), although Turkey claims limited derogations on the ratified European Convention on Human Rights; has not accepted compulsory ICJ jurisdiction |
| Turkmenistan | based on civil law system and Islamic law; has not accepted compulsory ICJ jurisdiction |
| Turks and Caicos Islands | based on laws of England and Wales, with a few adopted from Jamaica and The Bahamas |
| Tuvalu | NA |
| Uganda | in 1995, the government restored the legal system to one based on English common law and customary law; accepts compulsory ICJ jurisdiction, with reservations |
| Ukraine | based on civil law system; judicial review of legislative acts; has not accepted compulsory ICJ jurisdiction |
| United Arab Emirates | based on a dual system of Shari'a and civil courts; has not accepted compulsory ICJ jurisdiction |
| United Kingdom | based on common law tradition with early Roman and modern continental influences; has nonbinding judicial review of Acts of Parliament under the Human Rights Act of 1998; accepts compulsory ICJ jurisdiction, with reservations |
| United States | federal court system based on English common law; each state has its own unique legal system, of which all but one (Louisiana, which is still influenced by the Napoleonic Code) is based on English common law; judicial review of legislative acts; has not accepted compulsory ICJ jurisdiction |
| United States Pacific Island Wildlife Refuges | the laws of the US, where applicable, apply |
| Uruguay | based on Spanish civil law system; accepts compulsory ICJ jurisdiction |
| Uzbekistan | based on civil law system; has not accepted compulsory ICJ jurisdiction |
| Vanuatu | unified system being created from former dual French and British systems; has not accepted compulsory ICJ jurisdiction |
| Venezuela | open, adversarial court system; has not accepted compulsory ICJ jurisdiction |
| Vietnam | based on communist legal theory and French civil law system; has not accepted compulsory ICJ jurisdiction |
| Virgin Islands | based on US laws |
| Wake Island | the laws of the US, where applicable, apply |
| Wallis and Futuna | the laws of France, where applicable, apply |
| West Bank | void |
| Western Sahara | void |
| World | all members of the UN are parties to the statute that established the International Court of Justice (ICJ) or World Court |
| Yemen | based on Islamic law, Turkish law, English common law, and local tribal customary law; has not accepted compulsory ICJ jurisdiction |
| Zambia | based on English common law and customary law; judicial review of legislative acts in an ad hoc constitutional council; has not accepted compulsory ICJ jurisdiction |
| Zimbabwe | mixture of Roman-Dutch and English common law; has not accepted compulsory ICJ jurisdiction |