This study examined the contribution of school climate and culture in sustaining peace and good citizenship among students in bilingual secondary schools in Cameroon. The study was motivated by the need to understand how schools, especially in socially and linguistically diverse settings, can help learners live peacefully with others and develop responsible civic values. We adopted a concurrent mixed methods research design. The study was done in selected Government Bilingual Secondary Schools in four sub-divisions within the Bamenda and Yaoundé City Councils. The sample comprised 376 students and 10 teachers. Purposive sampling was used to select the schools and teachers, while students who had spent at least two years in the schools were selected through simple random sampling. Data were collected using a researcher-designed questionnaire for students and a Key Informant Interview guide for teachers. The quantitative data were analyzed using descriptive and inferential statistics, including frequencies, percentages, charts, regression, and chi-square, at the 0.05 level of significance. The qualitative data were organized into themes and interpreted in relation to the quantitative findings. The findings revealed that school culture/climate play a significant role in sustaining peace and good citizenship among students in bilingual secondary schools. School climate/ culture was a strong factor influencing peace and good citizenship. The results showed that students are more likely to develop peaceful attitudes, tolerance, cooperation, mutual respect, and civic responsibility when they learn in an environment that is inclusive, supportive, participatory, and respectful of linguistic and cultural diversity. Based on these findings, the study recommended that educational authorities, school administrators, and teachers should make deliberate efforts to strengthen multicultural practices that foster enabling school climate/cuture in schools. This could be done by promoting a peaceful and inclusive school climate to reflect cultural diversity, encouraging the use of multiple languages in learning, improving teacher preparation in multicultural and civic education, and giving students more opportunities to participate actively in school life. The study concluded that an enabling school climate and culture remains an indispensable means of promoting peaceful coexistence and good citizenship among students in Cameroon’s bilingual secondary schools.