Qusar is the capital and largest city of the Qusar District in Azerbaijan. It is situated in the northeastern part of the country within the Guba-Khachmaz Economic Region.
The district borders the districts of Quba, Qabala, and Khachmaz, as well as the Russian Republic of Dagestan. As of 2020, the population of the Qusar District was approximately 99,000 residents.