The Social Democratic Party is an East Timorese party founded on 20 September 2000. Despite its name, the party, like its Portuguese model, is usually categorised as centre-right in the political spectrum. It describes itself as being in the middle between left and right (centrist). The aim of the party's founders was to offer voters a moderate alternative to Fretilin and UDT. In 2002, the party had 8,000 members. Since then, the PSD has lost its importance. The PSD did not contest the 2023 parliamentary elections in East Timor.

The IV Constitutional Government was the fourth Constitutional Government under the Constitution of East Timor. Formed on 8 August 2007, it was led by the country's fifth Prime Minister, Xanana Gusmão, and was replaced by the V Constitutional Government on 8 August 2012.