Purpose <p>Stigmatizing attitudes towards individuals with mental illness are common among adolescents. Limited research exists on stigmatizing attitudes and causal beliefs about common mental disorders in adolescent populations in the Caribbean. This study seeks to understand the stigmatizing attitudes and beliefs about the causes of depression and social phobia (social anxiety) among adolescents in Bermuda.</p> Methods <p>This cross-sectional study surveyed students aged 10–19 years attending middle or high school in Bermuda. Online surveys conducted between November 2022 and June 2023 gathered data including demographics and symptoms of depression or anxiety, as well as correct problem recognition, stigmatizing attitudes and causal beliefs about a mental health problem described in a vignette.</p> Results <p>A total of 2,522 adolescents in Bermuda (70% of eligible participants) provided valid data for the depression (<i>n</i> = 1277) or social anxiety (<i>n</i> = 1245) vignette. Across both vignettes, reporting female gender was associated with less stigmatizing attitudes, while adolescents who identified their race as Black or Minority reported more stigmatizing attitudes. About three in ten adolescents reported a reluctance to disclose either social anxiety or depression. Respondents were more likely to believe in a psychosocial cause than a chemical imbalance cause of mental illness.</p> Conclusion <p>This study suggests there is a need to address stigmatizing attitudes among young people in Bermuda. In particular, anti-stigma campaigns need to be targeted to changing attitudes among those with higher stigma, including males or those reporting Black or Minority race.</p>