Organizational citizenship behavior (OCB), which is known as extra-role behavior, is an important factor for the organization to maintain the survival and achievement of organizational goals. OCB is very effective to be applied in human resource management because it can direct employees to provide performance that is more than just carrying out their formal duties. This study aimed to determine the influence of organizational culture, organizational justice, and organizational commitment to employee OCB at a vocational high school in the South Tangerang area, Indonesia. The research was quantitative study with a population of all school employees as many as 70 people. The sampling technique used nonpropability sampling, namely saturated samples. Data analysis was performed using a simple correlation analysis method and multiple linear regression with the help of IBM SPSS version 23. The results showed that organizational culture, organizational justice, and organizational commitment had a positive and significant effect on OCB either partially or simultaneously.