The persistent socio-economic and demographic inequalities that exist in the South African population have influenced the health-seeking behaviour of various groups, thereby resulting in health outcomes that can be described as being highly inequitable. This study aimed to evaluate the impact of socio-economic and demographic determinants on the health-seeking behaviour of the South African population in an attempt to add to the limited literature on the topic. A quantitative secondary analysis was conducted using the data from the National Income Dynamics Study Wave 4. Multivariate binomial logistic regressions were used to examine the socio-economic and demographic determinants of health-seeking behaviour. Some of the main findings were that women, the elderly and adults who were affiliated with quintile 5 had the highest odds of ever having visited a healthcare facility in the past year; whilst adults who had completed secondary education or resided on farms had the lowest odds. In relation to the type of healthcare facility last visited, adults who had a post-matric qualification belonged to wealth quintile 5 or who were married had the highest odds of going to a private healthcare facility. In contrast, adults who were unemployed who resided in traditional areas and women had the lowest odds of going to a private healthcare facility. The interaction effects investigated highlighted that in post-apartheid South Africa, gender and racial inequalities moderate the influence of selected socio-economic and demographic characteristics on the health-seeking behaviour of the population. Therefore, the present study concludes that both socio-economic and demographic determinants have a significant overall effect on the health-seeking behaviour of the South African population and suggests that future efforts to reduce health inequities should target the structural mechanisms of the social determinants of health.