Students become increasingly disconnected from their schools across the middle school years, but little is known about the factors contributing to changes in school connectedness. This study examined the time-invariant and time-varying roles of depressive symptoms and externalizing problems in trajectories of student-perceived school connectedness across the middle school years. Three yearly waves of data were collected from 296 students beginning in the sixth grade. Hierarchical linear modeling results indicated that school connectedness declined across time. Initial levels of adjustment problems at school entry were concurrently associated with lower levels of connectedness. Initial levels of externalizing problems did not account for rate of decline, but elevated levels of externalizing problems across the middle school years were associated with lower concurrent levels of connectedness. Surprisingly, initial levels of depressive symptoms predicted a slower rate of decline in connectedness for boys. Findings highlight the detrimental associations between adjustment problems and school connectedness.