Cameralism (German: Kameralismus) was a German science of public administration in the 18th and early 19th centuries that aimed at strong management of a centralized economy for the benefit mainly of the state. The discipline in its most narrow definition concerned the management of the state's finances. Throughout the 18th and the first half of the 19th century, cameralism was influential in Northern European states — for example, in Prussia and Sweden — and its academics and practitioners were pioneers in economic, environmental, and administrative knowledge and technology; for example, cameralist accounting, still used in public finance today.

The growing power of centralized state control necessitated centralized systematic information on the nation. A major renovation was the collection, use and interpretation of numerical and statistical data, ranging from trade statistics, harvest reports, and death notices to population censuses. Starting in the 1760s, officials in France and Germany began increasingly to rely on quantitative data for systematic planning, especially regarding long-term economic growth. It combined the utilitarian agenda of "enlightened absolutism" with the new ideas being developed in economics. In Germany and France, the trend was especially strong in cameralism and physiocracy. According to David F. Lindenfeld, it was divided into three: public finance, Oeconomie and Polizei. Here Oeconomie did not exactly mean 'economics', nor did Polizei mean 'public policy' in the modern senses.

Cameralism as a science is closely connected with the development of bureaucracy in the early modern period because it was a method aimed at increasing the efficiency of cameralists – not only referring to the academics devoted to the science but to those employed in the Kammer, the state administration. Cameralism was associated with the early modern term oeconomics, which had a broader meaning than the modern term economics as it entailed the stewardship of households, both public, private and by extension the state itself. Thus, oeconomics was a broader domain in which the investigation of nature merged seamlessly with concerns for material and moral well-being, in which the inter-dependence of urban and rural productivity was appreciated and stewarded, in which "improvement" was simultaneously directed toward increasing the yields of agriculture, manufacturing and social responsibility.

This further shaped cameralism as a wide discipline aimed at creating an overview of knowledge needed by an enlightened administrator. It also illustrates that practitioners of cameralism were a heterogeneous group that not only served the interest of the state but also that of the growing cadres of academics, scientists and technological experts striving for the favour of the state in order to further their own interests as well as being oeconomic patriots.

There are some similarities between cameralism as an economic theory and the French mercantilist school of Jean-Baptiste Colbert, which has sometimes caused cameralism to be viewed as a German version of mercantilism, as both emphasised import substitution and a strong state-directed economic life. However, cameralism was developed with regard to the landlocked nature of many of the German states of the 18th century and attempted to substitute the whole production process, whereas mercantilism relied on access to raw materials and goods from the colonial periphery. Furthermore, defining cameralism as an early modern school of economy does not accurately portray the scope of the body of knowledge included in cameralism.