The Social Democratic Party (Tajik: Ҳизби сотсиал-демократии Тоҷикистон, romanized: Hizbi Sotsial-Demokratii Tojikiston) is a centre-left political party in Tajikistan registered on 20 December 2002 and was led by Rahmatullo Zoirov until his death on May 18th, 2024.

[1] The history of the party's creation dates back to 18 March 1998, when the future members of the SDP established Tajikistan's Party of Justice and Progress.

[2] The party was registered on 9 February 1999, only to be suspended on 2 September 1999, which prevented it from participation in the Tajik Presidential Election.

One of the main opposition parties of Tajikistan, they boycotted both the 2006 and 2013 presidential elections.

[3] The party received 0.3 percent of the vote in the 2020 parliamentary election, winning no seats.