Opuzen is a small town in Dubrovnik-Neretva County in Croatia. It has a population of 3,242. The town is located 12 kilometres (7.5 mi) upstream from the mouth of the river Neretva, in southern Dalmatia. The valley of the Neretva River is also called the green valley. This settlement is known as a major center of tangerine production in Croatia.Opuzen got its name from its fortress, Fort Opus. The fortress was built by the Republic of Venice in 1684. Ruins of the fortress remains are called Recycle and are part of the old town wall. The center of the old part of Opuzen is a classic Roman Forum.
In the town is located Opuzen's Parish church of St. Stephen and it is in the main square. Important cultural and sport events related to Opuzen and the local countryside are "The Melodies of the Croatian South" and Opuzen Boat Marathon. The marathon is held on the river Neretva and about 35 boats participate each year.