Hisor (Tajik: Ҳисор) or Hisar (Russian: Гиссар, Gissar) is a city in western Tajikistan, about 15 km west of Dushanbe.

The fort of Hisar, residence of the Bukharan governor, is said to date back to Cyrus the Great and to have been captured twenty one times.

Hisar became a semi-independent principality in the next few decades and was ruled by a sultan, furnishing troops for Bukhara's military campaigns.

During this period the Bukharan khanate was split between the khan in Bukhara and the ruler (usually one of his relatives) in Balkh, and Hisar was generally subordinate to the latter.

The decline of Bukharan power after the assassination of Ubaydullah Khan in 1711 resulted in Hisor asserting its independence.