<![CDATA[This study aims to analyze the influence of transformational leadership, servant leadership, and spiritual leadership on Organizational Citizenship Behavior (OCB) among millennial employees in Boyolali Regency. This research employed a quantitative explanatory approach. The population consisted of millennial employees aged 30-44 years working in Boyolali Regency. A total of 223 respondents were selected using the Slovin formula. Data were collected through questionnaires using a Likert scale and analyzed using multiple linear regression with SPSS version 25. The results indicate that transformational leadership has a positive and significant effect on Organizational Citizenship Behavior (t = 3.407; p = 0.001). Servant leadership also has a positive and significant effect on Organizational Citizenship Behavior (t = 4.524; p = 0.000). Likewise, spiritual leadership has a positive and significant effect on Organizational Citizenship Behavior (t = 8.338; p = 0.000). Simultaneously, transformational leadership, servant leadership, and spiritual leadership significantly influence Organizational Citizenship Behavior (F = 167.319; p = 0.000). The coefficient of determination (R²) of 0.696 indicates that 69.6% of Organizational Citizenship Behavior is explained by the three leadership variables, while the remaining 30.4% is influenced by other variables outside this study. The findings imply that organizations should implement leadership practices that inspire, serve, and emphasize spiritual values to improve employees' voluntary work behavior.]]>
