Jevgeni Ossinovski is the mayor of Tallinn and former leader of the Estonian Social Democratic Party.

The Social Democratic Party is a centre-left political party in Estonia. It is currently led by Lauri Läänemets. The party was formerly known as the Moderate People's Party. The SDE has been a member of the Party of European Socialists since 16 May 2003 and was a member of the Socialist International from November 1990 to 2017. It is orientated towards the principles of social-democracy, and it supports Estonia's membership in the European Union. From April 2023, the party has been a junior coalition partner in the third Kallas government.