The Osh riots (Kyrgyz: Ош окуясы; Uzbek: Oʻsh voqeasi, Ўш воқеаси; Russian: Ошская резня) were an ethnic conflict between Kirghiz (Kyrgyz) and Uzbeks that took place in June 1990 in the cities of Osh and Uzgen, part of the Kirghizia. The immediate cause of the riots was a dispute between an Uzbek nationalist group Adolat and a Kyrgyz nationalist group Osh Aymaghi over the land of a former collective farm. While official estimates of the death toll range from over 300 to more than 600, unofficial figures range up to more than 1,000. The riots have been seen as a forerunner to the 2010 ethnic clashes in the same region.
Prior to the Soviet period, the inhabitants of the Osh region of the Fergana Valley referred to themselves as Kipchaks. In the 1920s, using language as the key determinant of ethnicity, Soviet ethnographers classified the lowland Kipchaks as Uzbeks and the highland Kipchaks as Kyrgyz. Although in the 1930s, Joseph Stalin divided the rich Fergana Valley among Kirghizia, Uzbekistan and Tajikistan, nationalities were not necessarily confined to the borders drawn for them. Along the "Kyrgyz" side of the Tentek-say River, there was a significant population of Uzbeks. Because of the region’s oil reserves, the local intelligentsia was able to obtain a significant degree of affluence, but infrastructure remained underdeveloped. During the Khrushchev era most of the deportees from the 1930s onward left to find better work elsewhere. By the late Brezhnev era, there were already signs of unemployment.