short form: Saint Vincent and the Grenadines

Samoa
conventional long form: Independent State of Samoa
conventional short form: Samoa
former: Western Samoa

San Marino
conventional long form: Republic of San Marino
conventional short form: San Marino
local long form: Repubblica di San Marino
local short form: San Marino

Sao Tome and Principe
conventional long form: Democratic Republic of
Sao Tome and Principe
conventional short form: Sao Tome and Principe
local long form: Republica Democratica de Sao Tome e Principe
local short form: Sao Tome e Principe

Saudi Arabia
conventional long form: Kingdom of Saudi Arabia
conventional short form: Saudi Arabia
local long form: Al Mamlakah al Arabiyah as Suudiyah
local short form: Al Arabiyah as Suudiyah

Senegal
conventional long form: Republic of Senegal
conventional short form: Senegal
local long form: Republique du Senegal
local short form: Senegal

Serbia and Montenegro
conventional long form: Serbia and Montenegro
conventional short form: none
local long form: Srbija i Crna Gora
local short form: none
former: Federal Republic of Yugoslavia
abbreviation: SCG

Seychelles
conventional long form: Republic of Seychelles
conventional short form: Seychelles

Sierra Leone
conventional long form: Republic of Sierra Leone
conventional short form: Sierra Leone

Singapore
conventional long form: Republic of Singapore
conventional short form: Singapore

Slovakia
conventional long form: Slovak Republic
conventional short form: Slovakia
local long form: Slovenska Republika
local short form: Slovensko

Slovenia
conventional long form: Republic of Slovenia
conventional short form: Slovenia
local long form: Republika Slovenija
local short form: Slovenija
former: People's Republic of Slovenia, Socialist Republic of Slovenia

Solomon Islands
conventional long form: none
conventional short form: Solomon Islands
former: British Solomon Islands

Somalia
conventional long form: none
conventional short form: Somalia
former: Somali Republic, Somali Democratic Republic

South Africa
conventional long form: Republic of South Africa
conventional short form: South Africa
former: Union of South Africa
abbreviation: RSA

South Georgia and the South Sandwich Islands
conventional long form:
South Georgia and the South Sandwich Islands
conventional short