Abakan (Russian: Абака́н [ɐbɐˈkan] ^ⓘ; Khakas: Ағбан Ağban, Абахан Abaxan) is the capital city of Khakassia, Russia, located in the central part of the Minusinsk Depression, at the confluence of the Yenisei and Abakan Rivers. As of the 2010 Census, it had a population of 165,214—a slight increase over 165,197 recorded during the 2002 Census and a further increase from 154,092 recorded during the 1989 Census.

Abakansky ostrog (Абаканский острог), also known as Abakansk (Абаканск), was built at the mouth of the Abakan River in 1675. In the 1780s, the selo of Ust-Abakanskoye (Усть-Абаканское) was established in this area. It was granted town status and given its current name on 30 April 1931.

In 1940, Russian construction workers found ancient ruins during the construction of a highway between Abakan and Askiz. When the site was excavated by Soviet archaeologists in 1941–1945, they realized that they had discovered a building absolutely unique for the area: a large (1500 square meters) Chinese-style, likely Han dynasty era (206 BC–220 AD) palace. The identity of the high-ranking personage who lived luxuriously in Chinese style, far outside the Han Empire's borders, has remained a matter for discussion ever since. Russian archaeologist Lidiya Yevtyukhova [ru] surmised, based on circumstantial evidence, that the palace may have been the residence of Li Ling, a Chinese general who had been defeated by the Xiongnu in 99 BCE, and defected to them as a result. While this opinion has remained popular, other views have been expressed as well. More recently, for example, it was claimed by Aleksey Kovalyov [ru] as the residence of Lu Fang [zh], a Han throne pretender from the Guangwu era.

In the late 18th and during the 19th century, Lithuanian participants in the 1794, 1830–1831, and 1863 rebellions against Russian rule were exiled to Abakan. A group of camps was established where prisoners were forced to work in the coal mines. After Stalin's death, Lithuanian exiles from the nearby settlements moved in.

Also Polish exiles were deported to Khakassia, with the some descendants still living in the region. In 1994, a local Polish school was founded, which was supported by the local authorities until 2014, and in 1999, a Polish-language faculty was introduced at the local Khakassian State University.

Abakan is the capital of the republic. Within the framework of administrative divisions, it is incorporated as the City of Abakan—an administrative unit with the status equal to that of the districts As a municipal division, the City of Abakan is incorporated as Abakan Urban Okrug.

The city has Katanov State University of Khakasia.

Abakan (together with Tayshet) was a terminal of the major Abakan-Taishet Railway.