This study explored the associations between secondary school students' sense of school belonging, their perceptions of school kindness, and character strength of kindness, and examined possible differences in these constructs across gender groups. The study, which included 1973 Hong Kong secondary school students, revealed that students' sense of school belonging was positively correlated with their perceptions of school kindness at the school and student levels (0.021 and 0.185, respectively). Furthermore, students' sense of school belonging was positively linked to character strength of kindness at the student level, although this relationship was found to be non-significant at the school level. At both levels of analysis, the positive relationships between students' perceptions of school kindness and character strength of kindness were significant. In addition, girls reported higher levels of character strength of kindness than boys. The findings of this study provide a better understanding of the relationships between sense of school belonging, school kindness, and character strength of kindness. Implications for research are also discussed. Copyright © 2020 Society for the Study of School Psychology.