Sukhumi or Sokhumi is a city in a wide bay on the Black Sea's eastern coast. It is both the capital and largest city of Abkhazia, a partially recognized state that most countries consider a part of Georgia. The city has been controlled by Abkhazia since the Abkhazian war in 1992–93. The city, which has an airport, is a port, major rail junction and a holiday resort because of its beaches, sanatoriums, mineral-water spas and semitropical climate. It is also a member of the International Black Sea Club.

Sukhumi's history can be traced to the 6th century BC, when it was settled by Greeks, who named it Dioscurias. During this time and the subsequent Roman period, much of the city disappeared under the Black Sea. The city was named Tskhumi when it became part of the Kingdom of Abkhazia and then the Kingdom of Georgia. Contested by local princes, it became part of the Ottoman Empire in the 1570s, where it remained disputed until it was conquered by the Russian Empire in 1810.

After a period of conflict during the Russian Civil War, it briefly became part of the Democratic Republic of Georgia, until it was again taken by the Bolsheviks. Within the Soviet Union, Sukhumi served as the capital of the Socialist Soviet Republic of Abkhazia and then the Abkhaz Autonomous Soviet Socialist Republic within the Georgian SSR. It was also a popular holiday destination. As the Soviet Union dissolved in the early 1990s, the city suffered significant damage during the Abkhaz–Georgian conflict. The present-day population of 60,000 is only half of the population living there toward the end of Soviet rule.

In Georgian, the city is known as Sokhumi (სოხუმი), amongst Samurzakanians in Megrelian the city is sometimes referred to as Aqujikha (აყუჯიხა), and in Russian as Сухум (Sukhum) or Сухуми (Sukhumi). The toponym Sokhumi derives from the Georgian word Tskhomi/Tskhumi (ცხომი/ცხუმი), which in turn is supposed to be derived from Svan tskhum (ცხუმ) meaning "hornbeam tree". In Abkhaz, the city is known as Aqwa (Аҟәа) which is believed to derive from a-qwara (а-ҟәара), meaning "stony seashore". According to Abkhaz tradition Aqwa (Аҟәа) signifies water.

Medieval Georgian sources knew the town as Tskhumi (ცხუმი). Later, under Ottoman control, the town was known in Turkish as Suhum-Kale (Ottoman Turkish: صخوم قلعه), which was derived from the earlier Georgian form Tskhumi or read to mean "Tskhumi fortress".

The ending -i in the above forms represents the Georgian nominative suffix. The town was officially called Сухум (Sukhum) in Russian until 16 August 1936, when this was changed to Sukhumi (Сухуми). This remained so until 4 December 1992, when the Supreme Council of Abkhazia restored the previous version. Russia also readopted its official spelling in 2008.

In English, the most common form today is Sukhumi, although Sokhumi is increasing in usage and has been adopted by sources including United Nations, Encyclopædia Britannica, Esri and Google Maps.

The history of the city began in the mid-6th century BC when an earlier settlement of the second and early first millennia BC, frequented by local Colchian tribes, was replaced by the Milesian Greek colony of Dioscurias (Greek: Διοσκουριάς). The city is said to have been founded and named by the Dioscuri, the twins Castor and Pollux of classical mythology. According to another legend it was founded by Amphitus and Cercius of Sparta, the charioteers of the Dioscuri. The Greek pottery found in Eshera, further north along the coast, predates findings in the area of Sukhumi bay by a century suggesting that the centre of the original Greek settlement could have been there.