Kavir Rural District () is in Sheshtaraz District of Khalilabad County, Razavi Khorasan province, Iran. Its capital is the village of Sad ol Din.
At the time of the 2006 National Census, the rural district's population was 6,171 in 1,637 households. There were 6,149 inhabitants in 1,883 households at the following census of 2011. The 2016 census measured the population of the rural district as 6,359 in 2,059 households. The most populous of its 39 villages was Sad ol Din, with 1,931 people.