Qahan Rural District () is in Qahan District of Jafarabad County, Qom province, Iran. Its capital is the village of Qahan.
At the National Census of 2006, its population (as a part of Khalajestan District of Qom County) was 4,260 in 1,348 households. There were 3,145 inhabitants in 1,159 households at the following census of 2011. At the most recent census of 2016, the population of the rural district was 2,900 in 1,117 households. The largest of its 25 villages was Qahan, with 784 people.
After the census, the rural district and the former Jafarabad District were separated from the county and divided into the Central and Qahan Districts, the former including the newly formed Baqerabad Rural District, and the latter containing the new Kohandan Rural District. The city of Jafariyeh was proclaimed capital of Jafarabad County.