The Republic of Montenegro holds a referendum proposing independence from the State Union of Serbia and Montenegro; 55% of Montenegrins vote for independence.

The Republic of Montenegro was a constituent federated state of the Federal Republic of Yugoslavia and then Serbia and Montenegro between 1992 and 2006. The declaration of independence of Montenegro in 2006 ended the ex-Yugoslav state. After the collapse of the Socialist Federal Republic of Yugoslavia (SFRY), the remaining republics of Montenegro and Serbia agreed to the formation of the Federal Republic of Yugoslavia (FRY) which officially abandoned communism and endorsed democratic institutions. Montenegro was a constituent republic of the FRY and its successor state until June 2006 when Montenegro declared independence from Serbia and Montenegro following the 2006 Montenegrin independence referendum.

An independence referendum was held in Montenegro on 21 May 2006. It was approved by 55.5% of voters, narrowly passing the 55% threshold. By 23 May, preliminary referendum results were recognized by all five permanent members of the United Nations Security Council, suggesting widespread international recognition if Montenegro were to become formally independent. On 31 May the referendum commission officially confirmed the results of the referendum, verifying that 55.5% of valid votes were in favor of independence. Because voters met the controversial threshold requirement of 55% approval, the referendum was incorporated into a declaration of independence during a special parliamentary session on 31 May. The Assembly of the Republic of Montenegro made a formal Declaration of Independence on Saturday, 3 June.

The State Union of Serbia and Montenegro, known until 2003 as the Federal Republic of Yugoslavia (FRY) and commonly referred to as Yugoslavia, was a country in Southeast Europe located in the Balkans that existed from 1992 to 2006, following the breakup of the Socialist Federal Republic of Yugoslavia. The state was established on 27 April 1992 as a federation comprising the Republic of Serbia and the Republic of Montenegro. In February 2003, it was transformed from a federal republic to a political union until Montenegro seceded from the union in June 2006, leading to the full independence of both Serbia and Montenegro.