Abstract <p>The article is devoted to a comprehensive analysis and systematization of methods for determining the boundaries (delineation) of urban agglomerations (conceptually close to metropolitan areas and functional urban areas in international practice) and their cores (urban areas) in Russian and foreign practice. The aim of the study is to determine the applicability of various methods and criteria for delineation at the stages of identifying minimum statistical units, forming urban areas, as well as existing and potential agglomerations. Seven methodological approaches used in determining the boundaries of agglomerations are considered: administrative, morphological, functional, network, economic, cognitive, and demographic. Each of them is characterized by its initial assumptions, scope of application, and limitations. It is shown that the morphological approach is most suitable for identifying urban areas, the functional approach is most appropriate for determining the boundaries of existing and potential agglomerations, and the administrative approach is most appropriate for subsequent adjustment of urban areas and agglomerations. The application of the systemic-structural paradigm made it possible to establish a correspondence between the stages of delineation and forms of settlement pattern: the minimum statistical unit is an element of the settlement pattern network, the urban area is a settlement pattern hub, the potential agglomeration is part of the territorial structure, and the established agglomeration is a territorial system. As a result of the study, the scope of application and limitations of each methodological approach at various stages of delineation were determined. The key problems arising in the practical use of criteria, such as the feasibility of using various administrative-territorial units at different stages of urban agglomeration delineation, the choice of reference points and means of transport for measuring distances and travel times, and the problem of “self-potential” in gravity models, are identified and analyzed, and solutions are proposed. It is shown that the choice of the delineation goal—identifying a territory with the potential for joint development (a potential urban agglomeration) or a territory with actually established intensive relationships (an established urban agglomeration)—is decisive for the final boundaries of the agglomeration. The obtained results provide the basis for developing unified approaches to identifying urban agglomerations and their cores in Russia.</p>