Historically, there have been various forms of religion-state relations in the world, most of which have evolved. The major models that characterise the relations between religion and state are the secular atheism model, theocratic model, strict separation model and the co-operationist model. These models can be generally considered as Weberian ideal types; that is, analytical representations of existing state practices vis-à-vis religion that abstracts from empirical realities. This article analyses the nature of relations between religion and state and the constitutional guarantees of religious freedom in South Africa. Having briefly discussed the four general structures of state-religion relations, the article argues that the South African model is characterised as ‘separation with interaction'. The article also argues such a model is rooted in the South African Constitution which highlights the centrality of religious freedom. The openness of the Constitution and flexible nature of relations between the South African state and religion provides a basis for the involvement of religious organisations in the public sphere has been the case with the National Interfaith Council of South Africa (NICSA).