The Siege of Dubrovnik (Serbo-Croatian: Opsada Dubrovnika, Опсада Дубровника) was a military engagement fought between the Yugoslav People's Army (JNA) and Croatian forces defending the city of Dubrovnik and its surroundings during the Croatian War of Independence. The JNA started its advance on 1 October 1991, and by late October, it had captured virtually all the land between the Pelješac and Prevlaka peninsulas on the coast of the Adriatic Sea, with the exception of Dubrovnik itself. The siege was accompanied by a Yugoslav Navy blockade. The JNA's bombardment of Dubrovnik, including that of the Old Town—a UNESCO World Heritage Site—culminated on 6 December 1991. The bombardment provoked international condemnation, and became a public relations disaster for Serbia and Montenegro, contributing to their diplomatic and economic isolation, as well as the international recognition of Croatia's independence. In May 1992, the JNA retreated to Bosnia and Herzegovina, less than 1 kilometre (0.62 miles) from the coast in some places, and handed over its equipment to the newly formed Army of Republika Srpska (VRS). During this time, the Croatian Army (HV) attacked from the west and pushed back the JNA/VRS from the areas east of Dubrovnik, both in Croatia and in Bosnia and Herzegovina, and by the end of May linked up with the HV unit defending the city. Fighting between the HV and Yugoslav troops east of Dubrovnik gradually died down.

The siege resulted in the deaths of 194 Croatian military personnel, as well as 82–88 Croatian civilians. The JNA suffered 165 fatalities. The entire region was recaptured by the HV in Operation Tiger and the Battle of Konavle by the end of 1992. The offensive resulted in the displacement of 15,000 people, mainly from Konavle, who fled to Dubrovnik. Approximately 16,000 refugees were evacuated from Dubrovnik by sea, and the city was resupplied by blockade-evading runabouts and a convoy of civilian vessels. More than 11,000 buildings were damaged and numerous homes, businesses, and public buildings were looted or torched.

The operation was part of a plan drawn up by the JNA aimed at securing the Dubrovnik area and then proceeding north-west to link up with the JNA troops in northern Dalmatia via western Herzegovina. The offensive was accompanied by a significant amount of war propaganda. In 2000, Montenegrin president Milo Đukanović apologized for the siege, eliciting an angry response from his political opponents and from Serbia. The International Criminal Tribunal for the former Yugoslavia (ICTY) convicted two Yugoslav officers for their involvement in the siege and handed a third over to Serbia for prosecution. The ICTY indictment stated that the offensive was designed to detach the Dubrovnik region from Croatia and integrate it into a Serb-dominated state through an unsuccessful proclamation of the Dubrovnik Republic on 24 November 1991. In addition, Montenegro convicted four former JNA soldiers of prisoner abuse at the Morinj camp. Croatia also charged several former JNA or Yugoslav Navy officers and a former Bosnian Serb leader with war crimes, but no trials have yet resulted from these indictments.