Abstract
This study applied social learning theory to understand how university students learned new health behaviors that impact their mental health through social media use. A cross-sectional research design was adopted with quantitative research methods to conduct the study. Data were collected using online questionnaires from a sample of 453 university students in Cameroon, Uganda and Nigeria. Data were analyzed using descriptive statistics, multiple hierarchical regression and structural equation modeling techniques. Findings revealed a negative significant relationship between outcome expectations and external locus of control. On the other hand, there was a positive significant relationship between external locus of control on mental health.It is recommended that content on social media platforms should aim at promoting the learning of positive health behaviors - thereby making users better, more acceptable people in society and trustworthy. Further, online community education, sensitization and policing should be conducted in order to help educate the careless learners on the dangers of social media on mental health. In terms of policy, governments should enact laws that encourage social media practitioners to use local content in order to ensure that appropriate and culturally proper information is consumed by citizens via social media.