Energy storage plays a crucial role in decarbonizing the global energy system, particularly in the heating sector, which accounts for nearly 50 % of global energy demand. However, a significant challenge remains in balancing supply and demand from renewable energy sources. High-Temperature Aquifer Thermal Energy Storage (HT-ATES) presents a promising solution by enabling seasonal energy storage and shifting thermal loads efficiently. The successful implementation of HT-ATES requires a comprehensive understanding of both subsurface geological conditions and surface constraints to identify optimal storage sites. This study introduces a favorability assessment framework for HT-ATES systems across the Swiss Molasse Plateau (SMP), utilizing spatial multi-criteria play-based analysis (SMCPBA). Two key geological targets—the Cenozoic Molasse and Upper Mesozoic formations—are assessed alongside energy system criteria to pinpoint high-potential areas for future development. The findings highlight major urban centers such as Geneva, Lausanne, and Zurich as prime candidates due to their significant heat demand. However, broad-scale estimations necessitate higher-resolution data and site-specific feasibility studies for accurate assessment and implementation. The scalability of this methodology makes it applicable to various geographic contexts, supporting targeted pilot projects and feasibility assessments. Advancing HT-ATES technologies through refined methodologies and practical applications will contribute to Switzerland’s sustainable energy transition and long-term energy resilience.