Behavioral intention is a crucial indicator of customer loyalty in the hospitality industry. This study examined whether social media marketing mediates the relationship between service quality and behavioral intention among customers of selected beach resorts in Mabini, Davao de Oro, Philippines. Although service quality and digital engagement have been widely studied, limited research has explored their combined effects in local tourism settings. Guided by the Theory of Planned Behavior, Expectation-Confirmation Theory, and SERVQUAL, the study proposed that social media marketing mediates the service quality–behavioral intention link. Using a descriptive-correlational design, data were gathered from 300 millennial customers who visited the resorts and interacted with Facebook ads. Mean scores, Spearman’s rho, and Structural Equation Modeling were used for analysis. Findings showed very high levels of service quality, social media marketing, and behavioral intention. Service quality strongly correlated with behavioral intention, while social media marketing had moderate correlation with service quality and a weaker relationship with behavioral intention. Mediation analysis revealed that social media marketing does not significantly mediate the relationship, indicating that service quality remains the strongest predictor of customer loyalty and revisit intention. The study highlights the need to prioritize service excellence while using social media as a supporting engagement tool.