Social Democratic Union may refer to:
*
Social Democratic Union (Croatia)
*
Social Democratic Union (Ireland), started by Tommy Broughan in 2014 after he left the Labour Party
*
Social Democratic Union (Latvia)
*
Social Democratic Union (Serbia)
The Social Democratic Union ( sr, Социјалдемократска унија, Socijaldemokratska unija; abbr. СДУ, SDU) was a minor social democratic and leftist political party in Serbia. In 2020 Party merged into Party of the Radical L ...
*
Social Democratic Union (Romania)
*
Social Democratic Union (Ukraine)
*
Social Democratic Union of Macedonia
The Social Democratic Union of Macedonia ( mk, Социјалдемократски сојуз на Македонија – СДСМ, ''Socijaldemokratski Sojuz na Makedonija'' – SDSM, sq, Lidhja socialdemokrate e Maqedonisë – LSDM) is a ...
*
Social Democratic Union of Workers and Smallholders
Social Democratic Union of Workers and Smallholders ( fi, Työväen ja Pienviljelijäin Sosialidemokraattinen Liitto, TPSL) was a political party in Finland. TPSL originated as a fraction of the Social Democratic Party of Finland, headed by Emil ...
, a political party in Finland
*
Social Democratic Union 'Proletarian', a political party in Bulgaria
*
Social Democratic Unionists, a political party in Syria
*
Polish Social Democratic Union, defunct political party in Poland
{{disambig, political