| Country | Legal system |
| Afghanistan | based on mixed civil and Shari'a law; has not accepted compulsory ICJ jurisdiction |
| Akrotiri | the Sovereign Base Area Administration has its own court system to deal with civil and criminal matters; laws applicable to the Cypriot population are, as far as possible, the same as the laws of the Republic of Cyprus |
| Albania | has a civil law system; has not accepted compulsory ICJ jurisdiction; has accepted jurisdiction of the International Criminal Court for its citizens |
| Algeria | socialist, based on French and Islamic law; judicial review of legislative acts in ad hoc Constitutional Council composed of various public officials, including several Supreme Court justices; has not accepted compulsory ICJ jurisdiction |
| American Samoa | NA |
| Andorra | based on French and Spanish civil codes; no judicial review of legislative acts; has not accepted compulsory ICJ jurisdiction |
| Angola | based on Portuguese civil law system and customary law; modified to accommodate political pluralism and increased use of free markets; has not accepted compulsory ICJ jurisdiction |
| Anguilla | based on English common law |
| Antarctica | Antarctica is administered through meetings of the consultative member nations; decisions from these meetings are carried out by these member nations (with respect to their own nationals and operations) in accordance with their own national laws; US law, including certain criminal offenses by or against US nationals, such as murder, may apply extraterritorially; some US laws directly apply to Antarctica; for example, the Antarctic Conservation Act, 16 U.S.C. section 2401 et seq., provides civil and criminal penalties for the following activities, unless authorized by regulation of statute: the taking of native mammals or birds; the introduction of nonindigenous plants and animals; entry into specially protected areas; the discharge or disposal of pollutants; and the importation into the US of certain items from Antarctica; violation of the Antarctic Conservation Act carries penalties of up to $10,000 in fines and one year in prison; the National Science Foundation and Department of Justice share enforcement responsibilities; Public Law 95-541, the US Antarctic Conservation Act of 1978, as amended in 1996, requires expeditions from the US to Antarctica to notify, in advance, the Office of Oceans, Room 5805, Department of State, Washington, DC 20520, which reports such plans to other nations as required by the Antarctic Treaty; for more information, contact Permit Office, Office of Polar Programs, National Science Foundation, Arlington, Virginia 22230; telephone: (703) 292-8030, or visit their website at www.nsf.gov; more generally, access to the Antarctic Treaty area, that is to all areas between 60 and 90 degrees south latitude, is subject to a number of relevant legal instruments and authorization procedures adopted by the states party to the Antarctic Treaty |
| Antigua and Barbuda | based on English common law |
| Arctic Ocean | void |
| Argentina | mixture of US and West European legal systems; has not accepted compulsory ICJ jurisdiction |
| Armenia | based on civil law system; has not accepted compulsory ICJ jurisdiction |
| Aruba | based on Dutch civil law system, with some English common law influence |
| Ashmore and Cartier Islands | the laws of the Commonwealth of Australia and the laws of the Northern Territory of Australia, where applicable, apply |
| Atlantic Ocean | void |
| Australia | based on English common law; accepts compulsory ICJ jurisdiction, with reservations |
| Austria | civil law system with Roman law origin; judicial review of legislative acts by the Constitutional Court; separate administrative and civil/penal supreme courts; accepts compulsory ICJ jurisdiction |
| Azerbaijan | based on civil law system; has not accepted compulsory ICJ jurisdiction |
| Bahamas, The | based on English common law |