This paper presents different historical and systematical approaches to point out the relationship between Catholic social teaching and social market economy. A fundamental connection between Catholic social teaching, ordoliberalism, and the market order is given in more detail. It becomes clear that not every form of capitalism is suitable for Catholic social teaching. However, the so-called “Rhenish capitalism”, i.e., social market economy, is the form of market economy that best coincides with the criteria of Catholic social teaching. This paper examines the anthropological and ethical foudations of the economic order in a detailed manner, especially of the economic order, especially the fundamental value of freedom as well as the notion of social justice by taking into account the importance of an ethos and an institutional framework. The idea of social market economy has to face current challenges and future perspectives which prove that – from an ethical point of view – the center of this discussion is the question of ineluctable standards of humanity and justice.