This is the first study that offers a comprehensive analysis of depression among the old (60+ years) in South Africa. This study uses four waves of a panel survey of the South Africa National Income Dynamics Study (SA-NIDS) during 2008-2014. A state-of-art econometric methodology has been used to unravel the factors underlying depression among the old over the period 2008-2014. Depending on whether the dependent variable is binary (self-reported depression for = 3 days in a week) or continuous (as in measures of overall depression and severe depression), we use random effects probit with Mundlak adjustment or simply random effects with Mundlak adjustment. Among the old, those more likely to be depressed are: those in their sixties, Africans and Coloureds, women, those suffering from multimorbidity, those with multiple limitations in ADLs, those in lower asset quartiles and individuals who suffered family bereavements. Factors that attenuate depression include marriage, pension, affluence, trust in a community and familiar neighbourhoods. An important feature of our study is the robustness of the key results. To reduce their depression, more public and private health care investment in the health and well-being of aged in South Africa is recommended.