Abstract <p>The spatiotemporal features of the sociodemographic development of the macroregion are examined, and possible scenarios of long-term sociodemographic development are substantiated. Sociodemographic development is a set of changes in social and demographic processes and their consequences and interactions in a particular territory in a specific period of time. Much emphasis is put on the processes of natural and migratory movement of the population, changes in the age–sex pattern of the population, and distribution of population in connection with socioeconomic processes. The study area is the Angara–Yenisei region (AYR), which includes four constituent entities of the Russian Federation: Krasnoyarsk krai, Irkutsk oblast, the Republic of Tyva, and the Republic of Khakassia. Changes at interrelated territorial levels, such as regions, constituent entities, and subregions (urban agglomerations), are considered. Geographical, cartographic, demographic, and statistical methods are used to assess the relationships between processes and structures. Three possible scenarios are proposed for sociodemographic development: inertia as basic, target as optimistic, and adaptive as realistic. The information base is literature and statistical sources. The data from the censuses of population (2002 and 2020), current records, and forecast calculations by Rosstat are used. The forecast scenarios can be used to develop strategies and measures for the sociodemographic development of the regions.</p>