Mental health status is fundamental to overall health and well-being but most studies on the relationship between migration and mental health status deal with international migration and neglects internal migration. Therefore, this study compares the mental health status of internal migrants with that of non-migrants; and also appraises the socio-demographic factors associated with mental health status in South Africa. Data were from the National Income Dynamics Study (NIDS), waves 3 (2012), and 4 (2014) of South Africa. Univariate analysis was used to describe the study population, bivariate analysis was use to explain the mental health status of the population, and binary logistic regression was used analyze the socio-demographic factors associated with mental health status. The study found significant differences in the mental health status of migrants and non-migrants across the waves of NIDS used for this study. While, the migrants had better mental health status in 2012, the non-migrants had better mental health status in 2014. In addition, factors significantly associated with mental health status in 2012, were marital status, income, and province of residence. On the other hand, only race, and province of residence were significantly associated with mental health status in 2014.