Social and political groups and parties, state, commerical and civil institutions.
- Social Democratic Federation (Melbourne) (c. 1895 - c. 1896)
- Social Democratic Federation of Australasia (1892 - )
- Social Democratic League (1889 - c. 1892)
- Social Democratic Party of Victoria (1902 - c. 1905)
- Social Democratic Vanguard
- Socialist Action
- Socialist Alliance (1993 - 1994)
- Socialist Alternative (1995 - )
- Socialist Comment
- Socialist Federation of Australasia
- Socialist Labor Party of Australia
- Socialist Party of Australia (I) (c. 1930 - c. 1970)
- Socialist Party of Australia (II) (1971 - 1996)
- Socialist Worker (1977 - 1989)
- Socialist Workers Action Group (1972 - 1974)
- Socialist Workers League (1970 - 1972)
- Socialist Workers Party (Australia) (1972 - 1989)
- Socialist Youth Alliance (1970 - 1980)
- Socialist (1974 - )
- Southerly: the magazine of the Australian English Association, Sydney.
- Southern Advocate for Workers' Councils (c. 1945 - )
- Southern Socialist Review
- see Southern Advocate for Workers' Councils (c. 1945 - ) - Soviet Union
- see Union of Soviet Socialist Republics (1917 - 1991) - SPA (1972 - 1974)
- Students United Against War (1991)
- Sydney Free University (1967 - 1972)
- Sydney University Labor Club (1925 - )