Qarah Quyun-e Jonubi Rural District () is in Qarah Quyun District of Showt County, West Azerbaijan province, Iran. It is administered from the city of Marganlar.
At the time of the 2006 National Census, the rural district's population (as a part of the former Showt District in Maku County) was 13,931 in 3,162 households. There were 4,360 inhabitants in 1,253 households at the following census of 2011, by which time the district had been separated from the county in the establishment of Showt County. The rural district was transferred to the new Qarah Quyun District. The 2016 census measured the population of the rural district as 4,421 in 1,345 households. The most populous of its 12 villages was Tazeh Kand-e Qadim, with 2,087 people.