The Social Democracy party (Istalian: Socialdemocrazia, SD) was a centre-left political party in Istalia. The party was founded in 3663 as a merger of two other parties, the Istalian Socialist Party and the Green Ecologist Party. These parties had previously cooperated in an electoral coalition known as The Olive Tree. The last chairman of Social Democracy was Alessandra Monti, who also served as Prime Minister of Istalia between 3667 and 3670. The party was dissolved in 3670.