Despite the important role public schools serve in students' lives, schools are an epicenter of racialized traumatic events for youth of color. School social workers are well positioned to lead racial equity in their schools and intervene to support more equitable outcomes for all students. Ample research has demonstrated educational inequities for these students, but no study to date has examined the impact of teacher racial bias on the quality of student-teacher relationships in U.S. pre-kindergarten through 12th grade schools. The purpose of this study was to understand the possible impact of interpersonal racism in the classroom, by examining whether teachers' perceptions of their own implicit and explicit racial bias related to the quality of their relationships with students, and if teacher-student racial mismatch moderated this relationship. Current teachers (N = 115) completed an online computer survey that included measures of implicit and explicit racial bias, teacher-student racial mismatch, and the quality of student-teacher relationships. Data were analyzed using multiple linear regression in SPSS. Results show teachers' explicit racial bias was a statistically significant predictor of the quality of student-teacher relationships. Implications are shared for school social work practice and research to advance educational justice.