Little is known about solitary living in sub-Saharan Africa, despite the prevalence of evidence in countries like South Africa showing that one-person households (OPHs) are on the rise. This paper examines the determinants of solitary living and the contribution of these factors to the rise in solitary living in South Africa. The analysis was based on 10% samples from three successive censuses of South Africa (1996, 2001, 2011). The multilevel binary logistic regression model was used to identify the determinants and a non-linear multivariate decomposition method was used to identify key contributing factors. The proportion of OPHs increased from 17.8% in 1996 to 27.5% in 2011. Living alone was found to be associated with various important demographic and socio-economic factors. Predominantly, the increase in solitary living in South Africa is attributed to compositional change of characteristics (68.5%) compared to change in the effects of characteristics (31.5%). The main contributing factors were compositional shifts in household ownership, household income level, migration and employment. More research on solitary living is needed to inform policy.