The Central District of Zarandiyeh County () is in Markazi province, Iran. Its capital is the city of Mamuniyeh.
After the 2006 National Census, the village of Khoshkrud was elevated to the status of a city. In 2021, Hakimabad Rural District and the city of Zaviyeh were separated from the district in the formation of Zaviyeh District.
At the time of the 2006 census, the district's population was 48,274 in 12,448 households. The following census in 2011 counted 49,344 people in 14,592 households. The 2016 census measured the population of the district as 53,852 inhabitants in 17,094 households.