Pliska (bulg.: Плиска) was the first capital of Danubian Bulgaria, between 681 and 893 AD. According to a Bulgarian chronicle it was founded by Khan Asparukh. It is called Pliskusa by Georgios Kedrenos and Anna Comnena. It had an area of 23 sq. km. and was surrounded by a moat and earthwork ramparts. The walls of the inner fortress were 2.6 meters thick and about 12 meters high.

Pliska was sacked by the Byzantine army in 811, but the invaders were soon driven out by Khan Krum. Khan Omurtag brought in artisans and craftsmen to improve the city. In 886, Boris I founded the Pliska Literary School (after 893 Preslav Literary School) which was headed by Naum of Preslav.

In 892, the city became the scene of a pagan revolt led by King Vladimir. After the crushing of the revolt, Vladimir was dethroned and the third son of Boris I, Simeon, was installed into power. One of the first steps of the new ruler was to move the capital to Preslav, a fortified town in the vicinity of Pliska, probably because of the steadily strong pagan influence in the old capital.

The importance of Pliska gradually waned throughout the 10th century with the concentration of power and resources in Preslav. The city was destroyed during the assualts of the Kievan Rus' and the Byzantine Empire between 969 and 972 and was not rebuilt again.

The ruins of Pliska lie 3 km north of the modern village of Aboba, recently renamed as Pliska. The site of the city is currently a National Archeological Reserve.