BACKGROUND School-based interventions to prevent the metabolic and musculoskeletal health risks associated with accumulation of sedentary behaviour have shown relative success. In resource limited environments, interventions that rely on teachers to delivery additional curricula or on parents’ engagement in learning materials may not be feasible. Interventions that alter the physical classroom environment and do not rely on additional capacity or are likely to succeed in reducing classroom sedentary behaviour. OBJECTIVE To systematically search, identify and summarize the effectiveness of classroom-based interventions aimed at reducing classroom sedentary behavior and improving spinal health. METHODS The review included experimental studies conducted exclusively in school classrooms that objectively measured classroom sedentary behaviour and spinal health measures. Four databases were searched in April 2021. Search terms related to sedentary behaviour, classroom sitting, classroom neck and back pain. Study findings were summarized in tables and a meat-analysis of homogenous review outcomes data was conducted. RESULTS Twelves experimental studies from high-income countries were included. Nine studies focused on SB and three on spinal health. All but one SB study reported decreases in classroom sitting time. The pooled medium-term effects of a subset of SB interventions showed a statistically significant decreases in sitting (p=0.03), while short and long-term effects were not significantly reduced (p=0.13 and p=0.23, respectively). A meta-analysis of spinal health studies reported statistically significant improvements in spinal behaviour during functional tasks (p=0.005). CONCLUSIONS Classroom-based interventions aimed at reducing SB and improving spinal health may be effective without placing additional burden on teachers and parents. Standardized outcomes for school-based SB are encouraged so findings from various settings may be pooled to determine overall effect across studies.