Socialist economics comprises the economic theories, practices and norms of hypothetical and existing socialist economic systems. A socialist economic system is characterized by social ownership and operation of the means of production that may take the form of autonomous cooperatives or direct public ownership wherein production is carried out directly for use rather than for profit. Socialist systems that utilize markets for allocating capital goods and factors of production among economic units are designated market socialism. When planning is utilized, the economic system is designated as a socialist planned economy. Non-market forms of socialism usually include a system of accounting based on calculation-in-kind to value resources and goods.

Socialist economics has been associated with different schools of economic thought. Marxian economics provided a foundation for socialism based on analysis of capitalism while neoclassical economics and evolutionary economics provided comprehensive models of socialism. During the 20th century, proposals and models for both socialist planned and market economies were based heavily on neoclassical economics or a synthesis of neoclassical economics with Marxian or institutional economics.

As a term, socialist economics may also be applied to the analysis of former and existing economic systems that were implemented in socialist states such as in the works of Hungarian economist János Kornai. 19th-century American individualist anarchist Benjamin Tucker, who connected the classical economics of Adam Smith and the Ricardian socialists as well as that of Pierre-Joseph Proudhon, Karl Marx and Josiah Warren to socialism, held that there were two schools of socialist thought, namely anarchist socialism and state socialism, maintaining that what they had in common was the labor theory of value. Socialists disagree about the degree to which social control or regulation of the economy is necessary; how far society should intervene and whether government, particularly existing government, is the correct vehicle for change are issues of disagreement. The goal of socialist economics is to neutralize capital, or in the case of market socialism to subject investment and capital to social planning.

Karl Marx and Friedrich Engels believed that hunter-gatherer societies and some primitive agricultural societies were communal, and called this primitive communism. Engels wrote about this at length in the book The Origin of the Family, Private Property and the State, which was based on the unpublished notes of Marx on the work of Lewis Henry Morgan.

Values of socialism have roots in pre-capitalist institutions such as the religious communes, reciprocal obligations and communal charity of medieval Europe, the development of its economic theory primarily reflects and responds to the monumental changes brought about by the dissolution of feudalism and the emergence of specifically capitalist social relations. As such it is commonly regarded as a movement belonging to the modern era. Many socialists have considered their advocacy as the preservation and extension of the radical humanist ideas expressed in Enlightenment doctrine such as Jean-Jacques Rousseau's Discourse on Inequality, Wilhelm von Humboldt's Limits of State Action, or Immanuel Kant's insistent defense of the French Revolution.

Capitalism appeared in mature form as a result of the problems raised when an industrial factory system requiring long-term investment and entailing corresponding risks was introduced into an internationalized commercial (mercantilist) framework. Historically speaking, the most pressing needs of this new system were an assured supply of the elements of industry (land, elaborate machinery, and labour) and these imperatives led to the commodification of these elements.

According to influential socialist economic historian Karl Polanyi's classic account, the forceful transformation of land, money and especially labour into commodities to be allocated by an autonomous market mechanism was an alien and inhuman rupture of the pre-existing social fabric. Marx had viewed the process in a similar light, referring to it as part of the process of "primitive accumulation" whereby enough initial capital is amassed to begin capitalist production. The dislocation that Polyani and others describe, triggered natural counter-movements in efforts to re-embed the economy in society. These counter-movements, that included, for example, the Luddite rebellions, are the incipient socialist movements. Over time such movements gave birth to or acquired an array of intellectual defenders who attempted to develop their ideas in theory.

As Polanyi noted, these counter-movements were mostly reactive and therefore not full-fledged socialist movements. Some demands went no further than a wish to mitigate the capitalist market's worst effects. Later, a full socialist program developed, arguing for systemic transformation. Its theorists believed that even if markets and private property could be tamed so as not to be excessively "exploitative", or crises could be effectively mitigated, capitalist social relations would remain significantly unjust and anti-democratic, suppressing universal human needs for fulfilling, empowering and creative work, diversity and solidarity.