The purpose of this study is to determine the features of regional differences in social development, the ways of their cognition and regulation. Regional differences in the level of social development from the perspective of inclusiveness are understood as inequality of individuals or groups in access to material goods and services. The receipt of monetary income by the population is only an instrument of access to them. Therefore, in order to develop methodological approaches and make managerial decisions, it is important to answer two questions: what specific material goods and services are considered within the framework of social inequalities, how to assess the level of the latter? However, the presence of regional differences in social development contributes to the search for real opportunities of regions in smoothing or leveling imbalances, identifying the sources of their occurrence. This approach made it possible to develop specific mechanisms to overcome social imbalances that will ensure inclusive regional development. From the totality of the sources of social inequalities in the regions, the problems of poverty of the population are chosen as the subject of research. Solving this problem is a key position in an integrated approach to regulating regional differences in social development. The methodology of the study is based on the calculation of the population poverty index according to the recommendations of the UNDP on four indicators. Based on these indicators, the calculation of the integral poverty index of the population and the grouping of regions of Kazakhstan are made. This approach will make it possible to introduce adequate tools for state support of various territories. Today, the identification and assessment of the level of poverty of the population is very relevant, since ensuring the sustainable development of regions does not allow ignoring situations of social inequalities in society.