The retention of Zillennial employees (born 1990–2005) presents significant challenges for contemporary organizations navigating competitive labor markets. This study investigates the relationships among perceived organizational support (POS), employee well-being (EWB), career development (CD), employee engagement (EE), and turnover intention (TI) within this workforce segment in Indonesia. Grounded in social exchange theory and complemented by conservation of resources theory, this research employed a quantitative cross-sectional survey design, collecting data from 360 Zillennial employees across multiple industries. Partial least squares structural equation modeling (PLS-SEM) tested the hypothesized relationships. Results indicate that POS (β = -0.285, p < 0.001) and CD (β = -0.198, p < 0.01) demonstrate significant negative direct effects on turnover intention, while EWB shows no significant direct relationship (β = -0.082, p > 0.05). All three antecedent variables significantly predicted employee engagement, which exhibited a strong negative relationship with turnover intention (β = -0.387, p < 0.001). Mediation analyses confirmed that employee engagement fully mediates the well-being–turnover relationship and partially mediates the effects of POS and CD. The model explained 64.8% of variance in turnover intention. These findings suggest that organizations seeking to retain Zillennial talent in Indonesia should prioritize organizational support systems, career development opportunities, and engagement-fostering initiatives. This study contributes to the literature by empirically examining these integrated relationships within an understudied demographic and cultural context, while acknowledging limitations inherent in cross-sectional, self-report designs.