Sustainable tourism has become a priority as environmental pressures on the hospitality sector intensify. Despite increasing promotion of green hotels, a persistent gap remains between pro-environmental intentions and actual booking behavior. Prior applications of the Theory of Planned Behavior (TPB) largely focus on developed economies and offer limited insight into how digital platforms, organizational credibility, and information-seeking behavior shape green hotel decisions in emerging tourism markets. To address this gap, this study extends TPB by integrating social media marketing, environmental knowledge, organizational green practices awareness, self-image in environmental protection, and consumer information-seeking behavior. Survey data from 538 foreign tourists staying in hotels in Turkey were analyzed using Partial Least Squares Structural Equation Modeling. The findings indicate that awareness of organizational green practices is the strongest predictor of consumer attitude, followed by self-image, social media marketing, and environmental knowledge. Consumer attitude, subjective norms, and perceived behavioral control shape purchase intention, while purchase behavior is driven by intention, perceived behavioral control, and information-seeking behavior. Notably, information-seeking behavior exerts a direct and mediating effect on purchase behavior but does not moderate the intention–behavior relationship, indicating a post-intentional verification role.