Low learning outcomes, especially among poor and marginalized students, are a pervasive problem in many low- and middle-income countries. Negative teacher beliefs and expectations may contribute to low learning outcomes among the poor, especially if they are reflected in classroom practices and interactions. Studies from various Southern contexts have shown that students from poor and marginalized backgrounds are more likely to be subject to stereotypical and deficit-oriented teacher beliefs, but the evidence is scattered and disconnected. This study therefore systematically reviews the empirical literature on teacher beliefs and their implications for the educational outcomes of disadvantaged students in the global South. We primarily focus on studies using a qualitative sociological approach, to complement an existing review that looks on the quantitative and econometric literature. Based on the findings, we develop a conceptual framework that identifies the structural and cultural determinants of teacher beliefs and the various mechanisms that link them to diminished wellbeing and educational achievement for disadvantaged students. The 55 empirical studies included in our review poignantly illustrate the degree of injustice and discrimination inflicted on the children of the poor as they navigate education systems around the world. We also highlight examples of positive teacher beliefs and practices, however, and discuss promising avenues for further research. Finally, we argue that any policy interventions aimed at changing teacher beliefs should be based on a contextualized understanding of these beliefs and their effects on learner engagement and achievement.