The Hague Convention of 1961, also known as the Convention Abolishing the Requirement of Legalization for Foreign Public Documents, is a multilateral treaty that simplifies the process of authenticating and legalizing public documents for use in other countries.
As of my knowledge cutoff, the following countries are members of the Hague Convention of 1961:
Albania
Andorra
Antigua and Barbuda
Argentina
Armenia
Australia
Austria
Azerbaijan
Bahamas
Bahrain
Barbados
Belarus
Belgium
Belize
Bosnia and Herzegovina
Botswana
Brazil
Brunei
Bulgaria
Cape Verde
Chile
China (Hong Kong and Macau only)
Colombia
Cook Islands
Costa Rica
Croatia
Cyprus
Czech Republic
Denmark
Djibouti
Dominica
Dominican Republic
East Timor (Timor-Leste)
Ecuador
Egypt
El Salvador
Estonia
Fiji
Finland
France
Gabon
Gambia
Georgia
Germany
Greece
Grenada
Guatemala
Guinea
Guinea-Bissau
Guyana
Honduras
Hungary
Iceland
India
Indonesia
Iraq
Ireland
Israel
Italy
Jamaica
Japan
Jordan
Kazakhstan
Kenya
Kiribati
Kuwait
Kyrgyzstan
Latvia
Lebanon
Lesotho
Liberia
Liechtenstein
Lithuania
Luxembourg
North Macedonia
Madagascar
Malawi
Malaysia
Maldives
Mali
Malta
Marshall Islands
Mauritania
Mauritius
Mexico
Moldova
Monaco
Mongolia
Montenegro
Morocco
Mozambique
Myanmar (Burma)
Namibia
Nauru
Netherlands
New Zealand
Nicaragua
Niger
Nigeria
Norway
Oman
Pakistan
Panama
Papua New Guinea
Paraguay
Peru
Philippines
Poland
Portugal
Qatar
Romania
Russia
Saint Kitts and Nevis
Saint Lucia
Saint Vincent and the Grenadines
Samoa
San Marino
Sao Tome and Principe
Saudi Arabia
Senegal
Serbia
Seychelles
Sierra Leone
Singapore
Slovakia
Slovenia
Solomon Islands
Somalia
South Africa
South Korea
Spain
Sri Lanka
Suriname
Swaziland
Sweden
Switzerland
Taiwan
Tajikistan
Tanzania
Thailand
Togo
Tonga
Trinidad and Tobago
Tunisia
Turkey
Turkmenistan
Tuvalu
Uganda
Ukraine
United Arab Emirates
United Kingdom
United States
Uruguay
Uzbekistan
Vanuatu
Vatican City
Venezuela
Vietnam
Yemen
Zambia
Zimbabwe
