Kahriz Siyah Mansur () is a village in Ijrud-e Pain Rural District of Halab District in Ijrud County, Zanjan province, Iran.
At the time of the 2006 National Census, the village's population was 150 in 37 households. The following census in 2011 counted 224 people in 69 households. The 2016 census measured the population of the village as 154 people in 52 households.