Influencer marketing has become a major expenditure for tourism organizations, as destinations increasingly rely on digital personalities to attract consumer attention. Despite its rapid growth, the effectiveness of influencers remains insufficiently understood. Given the rising importance of value co-creation for tourism stakeholders, this study examines how social media influencers affect tourists’ intentions to engage in value co-creation, with destination engagement and tourist well-being incorporated as mediating factors. Moreover, because similarity between influencers and their audiences is considered a determinant of influencer effectiveness, the study investigates the moderating role of self-congruity in the relationship between influencers and destination engagement. The research sample comprises social media users who follow at least one tourism or lifestyle influencer. A total of 780 questionnaires were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The results demonstrate that influencers significantly enhance tourists’ value co-creation intentions, with destination engagement and tourist well-being acting as key mediators. However, the moderating effect of self-congruity on the link between influencers and destination engagement was not supported. These findings contribute to a deeper academic and managerial understanding of how digital influencers shape tourist experiences and destination-related outcomes, offering a practical framework for fostering co-created value through influencer-driven engagement.