The Slovene Democratic Party (German: Slowenische Demokratische Partei), or SDP, is a now-defunct Austrian political party that existed between 1980 and 1995, when it merged with the Party for Istria to form the Democratic Party. The SDP was the federal sister party of the Slovene-nationalist Carniola Party (Krain Partei) that ruled the province of Carniola between 1984 and 2008.