The dynamics of population and number of settlements in diamond-mining areas of the Republic of Sakha (Yakutia) over a long historical period was assessed. The source materials of the study were archival statistical data of the All-Union (1959, 1970, 1979, 1989) and All-Russian population censuses (2002, 2010 and 2020), reference books of the administrative-territorial division of Yakutia, passports and strategies of socio-economic development of municipalities, archival documents and field materials. The main objective of the study has two components: identification of trends in the number of settlements and consideration of the impact of the diamond mining industry on the population dynamics of the studied areas. The main methods were the methods of geoinformation mapping, combining the possibilities of automated map construction based on classified indicators. The dynamics of the number of settlements was determined by mapping the difference of its values for 1959–2020, where 1959 is the year preceding the beginning of development of diamondiferous deposits in Western Yakutia. The population of the diamond mining areas doubled between 1959 and 2020. At the same time, the population growth and decrease in the share of the indigenous population in the total population during the Soviet period was replaced by population contraction and increase in the share of indigenous ethnic groups in the post-Soviet period. Against the background of overall population growth, there was a significant reduction in the number of settlements over the sixty-year period. The greatest compression of the settlement network was observed in areas where indigenous ethnic groups led a nomadic lifestyle. The geographical pattern of the settlement network with the predominance of sedentary population (Yakuts) was preserved, while the settlements themselves were enlarged. This conclusion is based on QGIS maps showing the location of settlements in the 8 studied uluses (districts) of Yakutia.