The increasing pressure on natural resources, rapid population growth, environmental degradation, and expanding tourism activities have raised significant concerns regarding sustainability. In this context, the concept of carrying capacity has emerged as an important framework for understanding the limits within which environmental, social, and economic systems can operate sustainably. Although originally developed in ecology, the concept has gained relevance in areas such as resource management, economic development, and tourism planning. This study examines the relationship between carrying capacity and sustainability through a qualitative secondary data analysis of ecological, human, and tourism perspectives. The study draws on existing scholarly literature to explore how environmental limits influence development activities and long-term sustainability. A thematic analysis was employed to identify major patterns and relationships within the literature. The findings indicate that carrying capacity is a dynamic concept influenced by resource availability, technological advancement, consumption patterns, governance systems, and environmental conditions. The study highlights that sustainability depends not only on the availability of resources but also on their efficient and responsible management. Furthermore, the analysis demonstrates that balancing economic growth, environmental protection, and social well-being is essential for achieving sustainable development. The study concludes that carrying capacity provides a useful framework for understanding sustainability challenges and guiding policy decisions. Integrating ecological, human, and tourism perspectives can help policymakers, businesses, and development planners promote sustainable growth while maintaining environmental integrity for future generations.