Purpose <p>This study aims to investigate the heterogeneity in attitudes toward homosexuality among secondary school students in Hong Kong and examine whether and how the attitude patterns had shifted between 2011 and 2021. Factors that influenced the attitude patterns were also examined.</p> Methods <p>Three dimensions of attitudes toward homosexuality were measured: general attitudes, attitudes toward formal rights, and attitudes toward informal privileges. Latent class analysis and multiple group latent class analysis were employed to analyze data from a repeated cross-sectional survey conducted in 2011, 2016, and 2021, involving a total of 10,769 adolescents.</p> Results <p>In 2011, three attitude classes were identified: intolerant, neutral, and inclusive. However, both 2016 and 2021 revealed a four-class model, consisting of three classes similar to those observed in 2011, and a new “partially inclusive” class. The prevalence of these attitude classes had shifted over the study period. Sex, age, sexual orientation, and exposure to online sexual knowledge were associated with the attitude patterns.</p> Conclusion <p>A notable increase in the acceptance of homosexuality was observed among Hong Kong adolescents from 2011 to 2021. However, their attitudes toward different topics of homosexuality were not entirely consistent.</p> Policy implications <p>This study provides valuable insights for policymakers and practitioners in assessing the compatibility of policies and practices with evolving attitudes. It underscores the importance of addressing not only the formal rights of sexual minority groups but also the more subtle, yet significant forms of discrimination they may face.</p>