In the social sciences, social structure is the aggregate of patterned social arrangements in society that are both emergent from and determinant of the actions of individuals. Likewise, society is believed to be grouped into structurally related groups or sets of roles, with different functions, meanings, or purposes. Examples of social structure include family, religion, law, economy, and class. It contrasts with "social system", which refers to the parent structure in which these various structures are embedded. Thus, social structures significantly influence larger systems, such as economic systems, legal systems, political systems, cultural systems, etc. Social structure can also be said to be the framework upon which a society is established. It determines the norms and patterns of relations between the various institutions of the society.

Since the 1920s, the term has been in general use in social science, especially as a variable whose sub-components needed to be distinguished in relationship to other sociological variables, as well as in academic literature, as result of the rising influence of structuralism. The concept of "social stratification", for instance, uses the idea of social structure to explain that most societies are separated into different strata (levels), guided (if only partially) by the underlying structures in the social system. There are three conditions for a social class to be steady, that of class cohesiveness, the self-consciousness of classes, and the self-awareness of one's own class. It is also important in the modern study of organizations, as an organization's structure may determine its flexibility, capacity to change, and success. In this sense, structure is an important issue for management.

On the macro scale, social structure pertains to the system of socioeconomic stratification (most notably the class structure), social institutions, or other patterned relations between large social groups. On the meso scale, it concerns the structure of social networks between individuals or organizations. On the micro scale, "social structure" includes the ways in which 'norms' shape the behavior of individuals within the social system. These scales are not always kept separate. Social norms are the shared standards of acceptable behavior by a group. When norms are internalized, they take on a "for granted" quality and are difficult to alter on the individual and societal levels.

The early study of social structures has considerably informed the study of institutions, culture and agency, social interaction, and history.

Alexis de Tocqueville was supposedly the first to use the term "social structure". Later, Karl Marx, Herbert Spencer, Ferdinand Tönnies, Émile Durkheim, and Max Weber would all contribute to structural concepts in sociology. The latter, for example, investigated and analyzed the institutions of modern society: market, bureaucracy (private enterprise and public administration), and politics (e.g. democracy).

One of the earliest and most comprehensive accounts of social structure was provided by Karl Marx, who related political, cultural, and religious life to the mode of production (an underlying economic structure). Marx argued that the economic base substantially determined the cultural and political superstructure of a society. Subsequent Marxist accounts, such as that of Louis Althusser, proposed a more complex relationship that asserted the relative autonomy of cultural and political institutions, and a general determination by economic factors only "in the last instance."

In 1905, German sociologist Ferdinand Tönnies published his study The Present Problems of Social Structure, in which he argues that only the constitution of a multitude into a unity creates a "social structure", basing his approach on his concept of social will.

Émile Durkheim, drawing on the analogies between biological and social systems popularized by Herbert Spencer and others, introduced the idea that diverse social institutions and practices played a role in assuring the functional integration of society through assimilation of diverse parts into a unified and self-reproducing whole. In this context, Durkheim distinguished two forms of structural relationship: mechanical solidarity and organic solidarity. The former describes structures that unite similar parts through a shared culture, while the latter describes differentiated parts united through social exchange and material interdependence.