Birun Bashm Rural District () is in Marzanabad District of Chalus County, Mazandaran province, Iran.

At the National Census of 2006, its population (as a part of the former Kelardasht District) was 5,852 in 1,602 households. There were 5,865 inhabitants in 1,923 households at the following census of 2011, by which time it became a part of the newly formed Marzanabad District. At the most recent census of 2016, the population of the rural district was 6,678 in 2,348 households. The largest of its 37 villages was Guytar-e Sofla, with 1,307 people.

References 

Chalus County

Rural Districts of Mazandaran Province

Populated places in Mazandaran Province

Populated places in Chalus County