The Social Democratic Party (Estonian: Sotsiaaldemokraatlik Erakond SDE) is a social-democratic political party in Estonia led by Sven Mikser. The SDE has been a member of the Party of European Socialists since 16 May 2003 and a member of the Socialist International since November 1990.The party was formerly known as the Moderate People’s Party (Estonian: Rahvaerakond Mõõdukad).The party’s youth wing is called Young Social Democrats.