This study examines the influence of social media engagement, brand authenticity, and consumer identity expression on brand loyalty among Generation Z, a cohort widely recognized for its strong digital presence and value-driven consumption behavior. As social media platforms increasingly shape consumer–brand interactions, understanding the mechanisms that drive loyalty within this segment has become critical for both scholars and practitioners. Drawing on established theories in digital marketing and consumer behavior, this research employs a quantitative approach using survey data collected from Generation Z respondents. The data were analyzed using multiple regression techniques to assess the relationships between the independent variables social media engagement, brand authenticity, and consumer identity expression and the dependent variable, brand loyalty. The findings reveal that all three factors significantly and positively influence brand loyalty. Social media engagement was found to enhance emotional and cognitive connections with brands, thereby strengthening loyalty. Brand authenticity emerged as a key determinant, indicating that Generation Z consumers are more inclined to support brands perceived as genuine, transparent, and consistent in their values. Additionally, consumer identity expression plays a crucial role, as individuals are more loyal to brands that align with and reinforce their self-concept and personal identity. Among the three predictors, brand authenticity demonstrated the strongest influence, highlighting the importance of trust and credibility in shaping long-term consumer relationships. This study contributes to the existing literature by integrating these three constructs into a single framework, offering a more comprehensive understanding of brand loyalty formation in the digital era. The results provide practical implications for marketers, emphasizing the need to foster authentic brand narratives, encourage interactive engagement on social media, and enable consumers to express their identities through brand affiliation. Despite its contributions, the study is limited by its cross-sectional design and reliance on self-reported data. Future research is recommended to explore longitudinal effects and additional moderating variables to better understand evolving consumer behaviors.