Sangdevin (Persian: سنگدوين) is a city in the Central District of Aliabad County, Golestan province, Iran.

At the 2006 census, its population was 3,671 in 862 households, when it was a village in Katul Rural District. The following census in 2011 counted 4,119 people in 1,180 households. The latest census in 2016 showed a population of 4,203 people in 1,255 households, by which time the village had been elevated to the status of a city.