Abstract Although numerous studies have examined factors that influence smartphone addiction, few have analyzed the potential protective factors inherent in individuals that may benefit future intervention programs for smartphone addiction. Thus, this study established a model for analyzing the mediating effect that learning self-efficacy and social self-efficacy have on the relationship between university students’ perceived life stress and smartphone addiction. Sampling 387 Taiwanese university students, we distributed scales surveying for university students’ life stress, learning self-efficacy, social self-efficacy, and smartphone addiction. Data retrieved from the scales were analyzed using structural equation modeling (SEM). The SEM path analysis yielded the following results: (1) Academic stress had negative predictive power for social and learning self-efficacies, and interpersonal relationship stress had negative predictive power for social self-efficacy. (2) Social self-efficacy had positive predictive power for smartphone addiction. (3) Family and emotional stresses had positive predictive power for smartphone addiction. Generally, the results of this study could be used to significantly predict the life stresses that influenced university students’ smartphone addiction. In addition, social self-efficacy can be considered a cognitive mechanism that mediates the relationships between academic stress and smartphone addiction and between interpersonal relationship stress and smartphone addiction. Finally, we discussed the research results and offered relevant suggestions for schools, university students, and future studies.