Background: Given the importance of school connectedness for healthy adolescent development, this scoping review aimed to identify and describe intervention strategies used to increase school connectedness among adolescents. Methods: Guided by the Arksey and O'Malley framework, we conducted a scoping review of school-based intervention studies published between 2011 and 2023 targeting school connectedness among adolescents. Intervention strategies were organized using a social-ecological framework. Findings: There were 24 included studies across 12 countries, targeting students aged 10-20 years. Various theories, study designs, and measurement tools were used. Interventions were primarily classroom-based, with common strategies including lessons, skill-building, and role plays. Most targeted the individual or interpersonal level rather than the organizational level. Despite it generally being a secondary outcome, 11 of the 23 interventions had a positive effect on school connectedness.