This integrative review examined correlates, mechanisms, and consequences of teacher bias experienced in pre-kindergarten through twelfth grade in primary and secondary schools in the United States. Education Resource and Information Center, Sociological Abstracts, and Applied Social Science Index & Abstracts were searched to identify peer-reviewed articles published in English from 2000-2020. Thirty-one articles were included. The majority (65%) of studies were qualitative and explored teachers' and students' perceptions of teacher bias or differential student treatment. Teacher bias was associated with students' race, ethnicity, immigration status, obesity, mental and physical disabilities. Behaviors associated with teacher bias included exclusionary discipline, microaggressions, name mispronunciations, and disproportionate gifted and special education referrals. Few studies quantitatively measured teacher bias suggesting methodological limitations in this body of evidence. Future research should employ objective measures of teacher bias. Research synthesis suggests teacher bias plays a significant role in teachers' perceptions of and behaviors towards diverse students.