Multimorbidity is an increasing global public health challenge, however, most existing research focuses on high-income countries, with limited evidence from low- and middle-income countries. This paper aims to estimate the prevalence of multimorbidity in South Africa and analyse the associations between multimorbidity and social determinants of health in the adult population. Multimorbidity will be defined as the coexistence of two or more chronic diseases in an individual throughout this paper. Data from the South African National Income Dynamics Survey of 2017 was used with a total sample of 20,833. A binary logistic regression was performed to analyse the associations between multimorbidity and several social determinants of health indicators based on the Commission on Social Determinants of Health Framework. Multimorbidity was prevalent in 5.4\% of the South African adult population surveyed, with 71.35\% of those with multimorbidity being female. Hypertension was the most common NCD and the highest contributor to multimorbidity. Multimorbidity was found to have statistically significant associations with age, obesity, being female, being of Colored or Asian/Indian ethnicity, being in employment, and having no schooling. This study highlights the importance of analysing the associations between multimorbidity and the social determinants of health. Further research on multimorbidity is required in low- and middle-income countries to understand the specific challenges not identifiable in the existing research predominately based in high-income nations.