["Journal of Product Innovation Management, EarlyView. ", "\nABSTRACT\nWhile establishing legitimacy is crucial for the diffusion of reverse innovation in developed markets, the mechanisms required to establish legitimacy remain underexplored. Drawing on product innovation and legitimacy studies, we use a mixed‐methods approach to provide a comprehensive understanding of legitimacy mechanisms for reverse innovation. Study 1 (qualitative phase) identifies and categorizes informational cues across three legitimacy mechanisms—identity, associative, and organizational, revealing how reverse innovations in packaged foods establish legitimacy through identity narratives, expert endorsements, and strategic certifications. Study 2 (quantitative phase) employs an experimental vignette methodology to validate how these mechanisms enhance different legitimacy dimensions and subsequently influence perceived value and purchase intention. Together, the studies reveal that while individual mechanisms enhance specific aspects of legitimacy perceptions, successful reverse innovation requires a holistic approach that addresses multiple legitimacy dimensions simultaneously. This research advances theoretical understanding of legitimacy‐building in reverse innovation, offers methodological novelty to the existing field, and provides key insights into aligning reverse innovation with consumer expectations in developed markets, thereby helping firms to overcome emerging market stigmatization, establish legitimacy, and facilitate the more effective diffusion of reverse innovation in developed markets.\n"]