This proof-of-concept study evaluated the relevance and applicability of ‘Individual Strengths, Collective Power!’, a character strengths-based program designed to improve classroom climate in inclusive Swiss schools. Inspired by the ‘Awesome Us!’ program, it incorporates five key steps: building shared language, recognizing others’ strengths, identifying own strengths, practicing strengths, and recognizing collective strengths. A simplified version was implemented in three classes of 9–12-year-olds over five weeks, with teachers using it thrice weekly. Students were assessed using the Positive and Negative Affect Schedule (PANAS) and a questionnaire survey, while teachers participated in a focus group. Results showed high interest in character strengths among students and teachers. Students’ positive affect increased significantly throughout the program. Both students and teachers provided positive feedback on the activities’ pedagogical quality, with students finding them engaging. Suggestions for improvement included clearer instructions and visual supports. The material proved relevant and applicable to the Swiss school context, indicating potential for larger-scale implementation. The study highlights the promise of strengths-based interventions in Swiss inclusive education and emphasizes the need for cultural and contextual adaptability. Limitations include a small sample size and potential subjectivity in data interpretation. Future research should evaluate the program’s efficacy on classroom climate and student relationships.