["Business Strategy and the Environment, EarlyView. ", "\nABSTRACT\nThis study examines how firms secure legitimacy in markets where faith‐based expectations and environmental responsibility intersect, focusing on halal–green cosmetics among Muslim women. It conceptualises halal trust and green trust as parallel legitimacy pathways reflecting faith‐based legitimacy and environmental credibility, respectively. Drawing on survey data from 382 respondents and analysed using PLS‐SEM, grounded in the value–attitude–behaviour framework, the findings reveal that halal trust exerts a stronger influence on consumer attitude than green trust, while ethical information disclosure strengthens favourable attitudes by reinforcing transparency and perceived accountability. Attitude emerges as the key interceding mechanism linking trust evaluations to purchase intention, whereas both trust constructs operate as baseline legitimacy conditions that enable, rather than amplify, purchase intention in ethically sensitive markets. The findings further indicate that trust functions as a strategic credibility mechanism under conditions of claim ambiguity. By framing dual trust as a legitimacy‐based mechanism, this study contributes to the literature on sustainability governance and value‐based market alignment.\n"]