Bizaki Rural District (Persian: دهستان بيزكي) is in the Central District of Golbahar County, Razavi Khorasan province, Iran. Its capital is the village of Shelangerd. The previous capital of the rural district was Mohsenabad.

At the National Census of 2006, its population (as a part of the former Golbahar District of Chenaran County) was 11,740 in 2,840 households. There were 10,885 inhabitants in 3,032 households at the following census of 2011. At the most recent census of 2016, the population of the rural district was 12,134 in 3,685 households. The most populous of its 118 villages was Now Bahar, with 2,367 people.

In August 2019, the district was separated from the county in the establishment of Golbahar County, which was divided into two districts of two rural districts each, with the city of Golbahar as its capital.