Teacher performance is one of the key factors in improving the quality of education. However, teacher performance at private vocational high schools in Cilegon City is still influenced by the implementation of school environmental governance, organizational culture, and organizational commitment; therefore, research is needed to obtain empirical evidence regarding the relationships among these variables. This study aims to analyze the influence of school environmental governance on teacher performance, organizational culture on teacher performance, school environmental governance on organizational commitment, organizational culture on organizational commitment, organizational commitment on teacher performance, as well as the mediating role of organizational commitment in the influence of school environmental governance and organizational culture on teacher performance. This study employs a quantitative approach using a survey method. The study population consisted of 127 teachers at three private vocational high schools in Cilegon City, with a saturation sampling technique used so that the entire population served as the sample. Data were collected using a five-point Likert-scale questionnaire and analyzed using Structural Equation Modeling-Partial Least Squares (SEM-PLS) via SmartPLS 4. The results indicate that school environmental governance has a positive and significant effect on teacher performance (t = 1.933; p = 0.030), organizational culture on teacher performance (t = 5.724; p = 0.000), school environmental governance on organizational commitment (t = 9.183; p = 0.000), organizational culture on organizational commitment (t = 11.673; p = 0.000), and organizational commitment on teacher performance (t = 2.577; p = 0.010). Organizational commitment also mediates the effects of school environmental governance (t = 2.390; p = 0.010) and organizational culture (t = 2.578; p = 0.010) on teacher performance. This study concludes that all hypotheses were accepted. School environmental governance, organizational culture, and organizational commitment have a positive and significant effect on teacher performance, while organizational commitment was found to mediate the effects of school environmental governance and organizational culture on teacher performance at private vocational high schools in Cilegon City