Globally, the need for sustainable urban development has never been more urgent than now. This is because estimates indicate that more than half of the global population will be living in urban areas by 2050, with South Africa estimated at 80%. This paper focuses on socio-economic nuances that impede sustainable urban development, as well as the strategies that can accelerate sustainable urban development in South Africa. Through a literature review methodology, the analysis identified the following issues as impediments to sustainable urban development in South Africa, informal settlements and businesses, lack of consultations with urban citizens, unresolved apartheid legacies, violence, crime and insecurity, and migration and immigration intricacies in South Africa. The paper also established the strategies to accelerate sustainable urban development as working with informality and against it, promoting inclusivity and access to resources, formulating, and accelerating policy reforms, investing in rural areas and towns, and finally investing in superior technology and innovation. These findings imply that there is a need to seek alternative development models and approaches, to address social challenges such as poverty, unemployment, and poor housing, aspects that impact negatively on urban development planning and sustainable development. This is because the major challenges to sustainable urban development are human-related challenges, that need social and economic solutions. There is also a need to reduce rural-urban migration by developing rural towns to ease pressure in major towns which are already spilling over.