Sergei Bagapsh (born 1949) has been the president of the unrecognized Republic of Abkhazia since 12 February 2005. He was also the fourth Prime Minister of the Republic of Abkhazia (a de facto independent republic of Georgia) from 27 April 1997 to December 1999.

Before being appointed as Prime Minister, Bagapsh had been a businessman, a former first secretary of the Abkhaz Komsomol and a permanent representative of the Abkhaz leadership in Moscow, Russia.

Bagapsh led Abkhazia at a time when there was a very real danger of renewed conflict with Georgia. He also led the entity while its President, Vladislav Ardzinba, was still able to govern effectively, so Bagapsh had much less power than some of his successors. Former Georgian President Eduard Shevardnadze once claimed that Bagapsh never passed any resolution without Ardzinba.

The Georgian-Abkhaz tensions during Bagapsh's rule came to a height in May, 1998, when the Tbilisi-based government-in-exile deployed forces along the Abkhaz-Georgian border. In the resulting conflict, which was colloquially named the "Six Day War", 30,000 Georgian refugees fled across the border to the town of Zugdidi. 1,695 houses occupied by Georgians were also burned down.

Bagapsh was the Abkhaz energy minister when he began to emerge as a likely opposition candidate in the leadup to the 2004 elections. On July 20, 2004, the two main opposition movements, Amtsakhara and United Abkhazia, named him as their joint candidate for the October presidential elections, beating out other hopefuls, such as former foreign minister Sergey Shamba. In the elections, Bagapsh and his main opponent, Raul Khadjimba, disputed the results. The Abkhaz Electoral Commission originally declared Khadjimba to be the winner, with Bagapsh a distant second, but the Supreme Court later found that Bagapsh had won with 50.3% of the vote. The court later reversed its decision after Khadjimba's supporters stormed the court building. At one point, Bagapsh and his supporters threatened to hold their own inauguration on December 6, 2004. However, in early December, Bagapsh and Khadjimba reached an agreement to run together on a national unity ticket. New elections were held on January 12, 2005, with this ticket easily winning. Under the agreement, Bagapsh campaigned for the position of president, with Khadjimba becoming vice-president if the arrangement is successful.