Social competence refers to having the behaviors, social skills, and intellectual capabilities needed to thrive in society. This includes the capacity to create, nurture, and maintain social relationships in various areas of life. This study investigates the effect of the Collaborative Constructivist Approach (CCA) to teaching social science on developing social competence and achievement in social science. Emotional maturity was considered as a covariate. The researcher selected two schools through a simple random sampling technique. The social competence scale of V.P. Sharma and Shukla and Shukla's emotional maturity scale by Yashvir Singh and Mahesh Bhargav, and the achievement test constructed and validated by the investigator were used. Descriptive statistics, including mean, median, mode, SD, and inferential statistics t-tests and ANCOVA, were used. The result reveals that the Collaborative Constructivist Approach is significantly more effective than the conventional method in fostering social competence and achievement in social science among secondary students.