This study aims to examine the effect of subjective well-being, knowledge management and trust in the employer on organizational citizenship behavior of Public Sector Governance Employees. This research method is a quantitative survey method. Respondents in this study were Public Sector Governance Employees totaling 680 employees. The selection of research subjects was carried out nonprobability with purposive sampling technique because it was based on the characteristics determined by the researcher. This study uses a Likert model scale of 1-7 as the main instrument in obtaining empirical data from knowledge management, organizational citizenship behavior, subjective well-being, and trust in the employer. Data was obtained through distributing online questionnaires via social media. Data analysis uses structural equation modeling (SEM) with SmartPLS 3.0 software tools. The results of the research hypothesis test are that Subjective Well-Being (SWB) has a positive and significant effect on Organizational Citizenship Behavior (OCB), Knowledge Management (KM) has a positive and significant effect on Organizational Citizenship Behavior (OCB), Trust in Employer (TIE) has a positive effect and significant to Organizational Citizenship Behavior (OCB).