Importance: Mental health stigma is a considerable barrier to help-seeking among young people.

Question: Are interventions aimed at reducing mental health stigma in young people associated with improved outcomes?

Findings: In this systematic review and meta-analysis of 97 randomized clinical trials involving 43 852 young people (aged 10-24 years), interventions had a significant short-term association with improvements in stigma-related knowledge, attitudes, and behaviors and help-seeking attitudes and intentions.

Meaning: These findings suggest that interventions to reduce mental health stigma may be effective in the short term, but further high-quality studies are needed to assess long-term outcomes.