Disengagement is a concept that captures the gradual behavioral, affective, and cognitive distancing from school, and is thus an early indicator of students being at risk for dropout. Based on a social identity framework, we predicted that higher social identification with the class and a positive classroom climate would be associated with lower rates of disengagement at both the individual and classroom level. In two samples from 16 German middle schools (n[subscript 1] = 255, n[subscript 2] = 287) with high annual dropout rates (> 10%), we assessed three disengagement facets: affect (daily mood at school), cognition (amotivation), and behavior (truancy). To examine both the individual and the classroom level, we utilized a 2-level mixed model. Gender, grade-level, and migration background were controlled in both samples, and economic learning resources (ELR) were included in sample 2 to better control for socioeconomic influences. In Study 1 (24 classrooms), we found a significant, positive association between social identification and daily mood at the individual level. In Study 2 (21 classrooms), we replicated initial findings for daily mood. In addition, social identification also impacted amotivation. At the class level, a higher grade, and a higher proportion of students with migration background were related to increased truancy. Classroom climate did not show a significant effect on disengagement in either of the studies. Our study sheds further light on the social dynamics of disengagement and highlights the need to control for classroom dynamics and student composition, particularly in classrooms with diverse student backgrounds.