Jovan Vladimir or John Vladimir ( Serbian Cyrillic: Јован Владимир; died 22 May 1016) was ruler of Duklja, the most powerful Serbian principality of the time, from around 1000 to 1016. He ruled during the protracted war between the Byzantine Empire and the First Bulgarian Empire. His close relationship with Byzantium did not save Duklja from the expansionist Tsar Samuel of Bulgaria, who conquered the principality in around 1010 and took Jovan Vladimir prisoner. A medieval chronicle asserts that Samuel's daughter, Theodora Kosara, fell in love with Vladimir and begged her father for his hand. The tsar allowed the marriage and returned Duklja to Vladimir, who ruled as his vassal.

Vladimir was acknowledged as a pious, just, and peaceful ruler. He took no part in his father-in-law's war efforts. The warfare culminated with Samuel's defeat by the Byzantines in 1014; the tsar died soon afterward. In 1016 Vladimir fell victim to a plot by Ivan Vladislav, the last ruler of the First Bulgarian Empire. He was beheaded in front of a church in Prespa, the empire's capital, and was buried there. He was soon recognized as a martyr and saint; his feast day is celebrated on 22 May. His widow, Kosara, reburied him in the Prečista Krajinska Church, near his court in southeastern Duklja. In 1381 his remains were preserved in the Church of Saint Jovan Vladimir near Elbasan, and since 1995 they have been kept in the Orthodox cathedral of Tirana, Albania. The saint's remains are considered relics, and attract many believers, especially on his feast day, when the relics are taken to the church near Elbasan for a celebration.