This study aims to determine the partial and simultaneous effects of Support Teamwork, Organizational Support, and Organizational Culture on Employee Performance at the Department of Population and Civil Registration of Ponorogo Regency. The research method used is a quantitative approach. The population in this study consists of all employees at the Department of Population and Civil Registration of Ponorogo Regency, with a sample size of 63 respondents selected using a saturated sampling technique. Data were collected through the distribution of questionnaires and analyzed using validity tests, reliability tests, multiple linear regression analysis, coefficient of determination ($R^2$), and hypothesis testing (t-test and F-test) utilizing SPSS.The results of the study indicate that: 1) Support Teamwork partially has a positive and significant effect on employee performance. 2) Organizational Support partially has a positive and significant effect on employee performance. 3) Organizational Culture partially has a positive and significant effect on employee performance. 4) Simultaneously, Support Teamwork, Organizational Support, and Organizational Culture have a positive and significant effect on Employee
Performance.Keywords: Support Teamwork, Organizational Support, Organizational Culture, Employee Performance.