Manbij District is a district of Aleppo Governorate in northern Syria. The administrative centre is the city of Manbij. At the 2004 census, the dis…Manbij District is a district of Aleppo Governorate in northern Syria. The administrative centre is the city of Manbij. At the 2004 census, the district had a population of 408,143. A 2019 report has estimated the population of Manbij district at 450,000 with 80% of the population being Arab, 15% Kurdish and 5% Turkmen and Circassian.