In this chapter, we propose the adoption of the paradigm of Economia Aziendale to refer to the application of a general theory of economic behaviour to the functioning of social institutions, as it has developed in Italian academia over the past several decades. We opt to keep the Italian words Economia Aziendale and Azienda in order to underline the difference between this paradigm and the business economics or public management, as it has spread internationally, especially in the anglophone world. Economia Aziendale was proposed at the beginning of the twentieth century as a convergence of two branches of knowledge: economics and accounting. The Economia Aziendale paradigm is based on four pillars: the socio-natural institution, socio-political institution, socio-economic institution, and socio-ideal institution. The chapter delineates the contours of such a paradigm, how it reached its maturity around the turn of the millennium, and its contemporary significance. Some of the contributions of Economia Aziendale include an appreciation that the public sector cannot be considered as a homogeneous entity, rather that it is composed of a large number of autonomous or semi-autonomous organizations, and an orientation of public management towards improving public administration, by starting from citizens’ rights and expectations, then defining the outputs to be produced, to then engage in the continuous redesign of administrative processes and procedures. A line of future development of the paradigm of Economia Aziendale lies in strengthening the interdisciplinary dialogue.