This study investigates how generational differences shape the relationship between pay equity and job engagement in multigenerational workplaces. Drawing on survey data from 458 white-collar employees in South Korea, the analysis examined three dimensions of pay equity: internal, external, and procedural, and tested the moderating role of generation using hierarchical regression. The results revealed that internal and procedural pay equity significantly enhance job engagement, whereas external pay equity showed no direct effect. Moreover, generation moderated the equity–engagement relationship: MZ employees were more responsive to perceived equity, particularly in transparent and consistent pay procedures, while older generations exhibited more stable engagement regardless of perceived equity levels. These findings suggest that lower engagement among MZ employees is not inherent but reflects unmet expectations regarding transparency and consistency in compensation. The results remained robust across alternative generational classifications and age controls. This study contributes to organizational behavior research by clarifying when and for whom pay equity matters most and emphasizes the need for differentiated compensation strategies in multigenerational workforces, particularly highlighting the importance of procedural and internal equity for engaging MZ employees.