Estalkh Zir (Persian: اسطلخ زير)[a] is a village in Sheykh Neshin Rural District of Shanderman District, Masal County, Gilan province, Iran.

At the time of the 2006 National Census, the village's population was 815 in 218 households.

[5] The 2016 census measured the population of the village as 803 people in 267 households.

It was the most populous village in its rural district.

This Masal County location article is a stub.