Vojislav Koštunica (Serbian Cyrillic: Војислав Коштуница, listen (help·info)) (pronounced , born 24 March 1944, Belgrade, Yugoslavia, now Serbia) is a Serbian politician and the President of the Democratic Party of Serbia. He was the last President of the Federal Republic of Yugoslavia, succeeding Slobodan Milošević and serving from 2000 to 2003. He also served two terms as the Prime Minister of Serbia, from 2004 to 2007 and from 2007 to 2008.

A graduate from the University of Belgrade's Law School with a Ph.D., Koštunica lost his job as Professor of Law at this institution in 1974, after criticizing Josip Broz Tito's Communist government. In 1989, he became one of the founders of the Democratic Party. He left the Democratic Party in July 1992 over opposing views in leadership and formed the Democratic Party of Serbia (DSS), of which he is still president.

Koštunica is a conservative politician with no connection to the old Communist Party (from which Slobodan Milošević's party originated). Supported by both nationalistic and pro-Western voters, the Democratic Opposition of Serbia backed him in the presidential election of September 2000. After turbulent events of October 2000, Koštunica was finally declared the winner of the election and remained president of the Federal Republic of Yugoslavia until February 2003, when the state was replaced by Serbia and Montenegro and the position he held was abolished. Koštunica opposed the extradition of his predecessor, Slobodan Milošević, and has stated his opposition to the Hague Tribunal several times.