The current Constitution of the Republic of Serbia (Serbian: Устав Републике Србије, romanized: Ustav Republike Srbije), also known as Saint Demetrius Day Constitution (Митровдански устав, Mitrovdanski ustav), is the supreme and basic law of Serbia. It was adopted in 2006, replacing the previous constitution dating from 1990.

The adoption of current constitution became necessary in 2006 when Serbia restored its independence following Montenegro's secession and the subsequent dissolution of Serbia and Montenegro. The proposed text of the constitution was adopted by the National Assembly on 30 September 2006 and put on constitutional referendum which was held on 28–29 October 2006. After 53% of the electorate voted in favor of the proposed constitution, it was officially adopted on 8 November 2006.

A constitutional referendum was held again on 16 January 2022, in which voters decided on changing the constitution in the provisions related to the judiciary. To bring the judiciary into line with European Union legislation, the Government of Serbia had previously proposed changing the way judges and public prosecutors are elected. After the adoption of constitutional changes, the National Assembly would have less influence on the election of certain judicial factors, such as the president of the Supreme Court, court presidents, public prosecutors, judges, and deputy public prosecutors. The National Assembly would then only elect four members of the High Judicial Council, High Prosecutorial Council, and the Supreme Public Prosecutor. The High Judicial Council would instead get a more important role by electing all judges, while the High Prosecutorial Council would elect prosecutors. The Supreme Court of Cassation's name would also be changed to the Supreme Court and its work would be more regulated. Government officials stated their support for such changes, while the opposition remained divided; most stated their objection to the referendum while some even called for a boycott or for the referendum to be postponed. The "yes" option prevailed over the "no" option in the referendum, although turnout was reported to be the lowest since 1990, at only 30% of voters in total. Constitutional changes were adopted by the National Assembly on 9 February.

Serbia was one of the first European countries to adopt a modern constitution in the 19th century, with the 1835 Constitution (also known as the Candlemas Constitution), following France (1791), Spain (1812), Norway (1814), the Netherlands (1814/1815), and Belgium (1831). This was a significant milestone, as it established Serbia as a pioneer in constitutionalism in Central and Eastern Europe, during a time when most European states lacked formal constitutions.

The Constitution contains a preamble, 11 chapters, and 206 articles.

The constitution of contains a preamble:

The constitution is divided into 10 chapters:

Among the differences between the current and previous constitution are: