BackgroundSocial self-efficacy (SSE) is a key cognitive-motivational construct predicting social adjustment and mental health. However, existing SSE scales were developed in Western individualistic cultures, neglecting collectivistic characteristics (e.g., relational harmony, emotional restraint) and online social contexts. This study developed and validated a culturally adapted multidimensional College Students ‘Social Self-Efficacy Questionnaire (CSSEQ) for Chinese students.MethodsA mixed-meth