This study investigated the structural relationships among self-advocacy, multicultural competencies, and social justice advocacy competencies for elementary, middle, and high school teachers responses were collected from 707 teachers nationwide, and a model of the relationships between variables was analyzed. The are as follows. First, a significant positive correlation was found among the three variables. Second, the fit of the model which established that multicultural competencies mediated the relationship between self-advocacy and social justice advocacy competencies was good. Additionally, the analysis showed that the direct effect of self-advocacy on social justice advocacy competencies and the indirect effect of self-advocacy through multicultural competence to social justice advocacy competencies statistically significant. This confirmed that multicultural competencies partially mediate the relationship between self-advocacy and social justice advocacy competencies. Third, this model did not show any differences by gender, working school level, or age group of teachers, indicating that this structural relationship can be generalized to all teachers. This study showed that self-advocacy and multicultural competencies need to be improved in tandem to increase social justice advocacy competencies.