Although cultural and leisure activities are critical for the healthy development of adolescents, research examining this topic among multicultural adolescents is rare. Therefore, this study investigates the influence of cultural and leisure activities on social competence among multicultural adolescents, with particular attention to examining the mediating effects of acculturative stress and self-esteem. Utilizing data from the 2nd Multicultural Adolescents Panel Study, direct, simple mediating, and dual mediating effects were analyzed with Model 6 of the PROCESS Macro method. The analyzed results show that multicultural adolescents’ cultural and leisure activities had a positively significant influence on social competence. Also, multicultural adolescents’ acculturative stress and self-esteem, respectively, had a simple mediating effect on the association between cultural and leisure activities and social competence. In addition, multicultural adolescents’ acculturative stress and self-esteem had a dual mediation effect. In that, the level of cultural and leisure activities decreased the level of acculturative stress, which, in turn, increased the level of self-esteem and finally increased the level of social competence. Strategies to enhance multicultural adolescents’ social competence through cultural and leisure activities are discussed based on the findings.