["Business Strategy and the Environment, EarlyView. ", "\nABSTRACT\nCircular business strategy (CBS) is increasingly adopted in the fashion industry to move beyond “take–make–dispose,” but performance measurement remains uneven and is often reported as separate metric sets. This study develops a data‐driven guide for evaluating CBS performance in the fashion industry. Content and cluster analyses were conducted to identify candidate indicators, which were organized into seven CBS attributes aligned with three circular principles. A fuzzy Delphi panel validated 28 CBS performance indicators (CBSPIs), and fuzzy DEMATEL was used to map perceived cause–effect relationships across attributes and indicators. Business modeling, strategic internal processes, waste management, and business scalability act as driver attributes, whereas cost management, regenerative performance, and regenerative governance serve as outcomes. Six indicators emerge as key levers for action sequencing: Industry 4.0 implementation, business model redesign, carbon dioxide reduction, circular differentiation, resource recovery facilities, and modular product design. These findings contribute to CBS research by validating an indicator system and ordering CBS attributes and indicators into a causal structure that distinguishes upstream drivers from downstream outcomes. The resulting CBSPIs support prioritization and monitoring during the implementation of circular strategies.\n"]