The article considers the resilience of old-industrial and mining regions as the ability to maintain significant socio-economic functions under adverse conditions, recover from disruptions, and change the development strategy if a return to the previous model reproduces previous vulnerabilities. The author analyses such definitions as resilience, sustainability, adaptability, and transformability. The article shows that the industrial heritage forms both a development resource for such territories – production links, infrastructure, and professional competencies – and limitations related to sectoral concentration, the state of infrastructure, and accumulated environmental damage. The author considers opportunities for applying ISO 37123:2019 “Sustainable cities and communities – Indicators for resilient cities, IDT” for the analysis of old-industrial regions. The article proposes an approach, according to which resilience is linked to the sustainable competitiveness of a territory through the economic diversification, technological renewal, human capital development, infrastructure modernization, and restoration of natural functions. Using the examples of the territory of advanced socio-economic development in Naberezhnye Chelny and the environmental “Sulfur Program” in Norilsk, the author shows that the presence of a management decision or the launch of a separate project cannot be automatically equated with a reduction in the structural vulnerability of a territory. The conceptual approach is based on the integrated analysis of the economic, social, infrastructural, environmental, and institutional components of the regional system, with indicators categorized according to their temporal role: baseline vulnerability, response to impact, functional recovery, and long-term structural change. It is argued that the unit of analysis should encompass not only individual enterprises and industries but also the interconnections among the population, the economy, utility and transport networks, governance institutions, and the natural environment. The study demonstrates that assessing diversification requires considering employment structures, the stability of new production linkages, and the extent to which new enterprises depend on legacy markets and infrastructural constraints. It is proposed that technological modernization be evaluated based on realized metrics of productivity, resource and environmental efficiency, safety, employment, and environmental quality, while human capital development is assessed through the demand for new skill sets and subsequent employment outcomes. Requirements are established for defining territorial boundaries, impact scenarios, data sources, observation periods, and rules for interpreting indicators. These findings provide a conceptual framework for the subsequent empirical validation of the approach using regional and municipal data, as well as for developing a replicable monitoring system for the resilience of old-industrial and mining regions.