Non-territorial autonomy is a form of self-determination in which the autonomous are not population groups living in a territory with defined borders, but rather communities defined by linguistic, cultural, and religious features, which, in many cases, features’ preservation is facilitated according to the terms of the group’s autonomy within the state.

Although means of social organization similar to non-territorial autonomy were also present in the distant past (the most famous of them is the millet system of the Ottoman Empire), the modern understanding of non-territorial autonomy is based on the works of Austrian social democrats Karl Renner and Otto Bauer published in the last years of the 19th and first years of the 20th century. They proposed an autonomy model which was aimed to find a solution to the problems and conflicts caused by the ethnic diversity in Austria-Hungary. However, various forms of non-territorial autonomy implemented today can be multifaceted and they may not have any connection with the vision of Renner and Bauer.

Non-territorial autonomy may be applied in practice or considered suitable in theoretical discussions, for example, to manage diversity inside a state, including for mitigating ethnic conflicts and preventing separatist sentiments among minorities. In addition, non-territorial autonomy can be one of the power sharing measures that increase the involvement of minority groups in decision making processes. Non-territorial autonomy is considered particularly suitable for the protection of the interests of dispersed communities, but it has also been considered suitable for, for example, indigenous peoples whose interests are actually often territorial. Thus, non-territorial autonomy may not function well as a completely independent measure, but may be combined with various means of territorial diversity management.

Non-territorial autonomy is an umbrella term and highly contested concept, the meaning of which is interpreted differently by both researchers and practitioners. This term has been used either as a synonym or as a connected term with several other concepts with a similar meaning, such as national personal autonomy, personal autonomy, national cultural autonomy, cultural autonomy, extraterritorial autonomy, corporate autonomy and segmental autonomy. In addition, non-territorial autonomy has been associated with consociationalism and plurinationalism. Alexander Osipov, a researcher of non-territorial autonomy, has found that although all of these concepts may have their own shades of meaning, non-territorial autonomy is the broadest and at the same time a neutral term. Some scholars argue that the term is not appropriate and too vague as most instances being labeled as "non-territorial autonomy" are neither non-territorial in a strict sense nor cases of political rule and autonomy, but of minority protection. The term is thus said to contribute to the conceptual confusion in the field.

In general, among political scientists and other researchers of non-territorial autonomy, it is considered most natural to associate this concept with the Austrian social democrat Karl Renner. Mentioning Renner (and somewhat less often also Otto Bauer) as a pioneer and one of the most important theorists of non-territorial autonomy is standard practice in academic publications on the subject.

According to political scientist John Coakley, some phenomena similar to non-territorial autonomy existed already in medieval Europe. As one example, he has pointed out that the King of Bohemia allowed the Germans residing in the state to live according to their own legal system. Similar autonomous rights were granted by other monarchs as well. As another example, Coakley has described the autonomy of Jews in the Polish-Lithuanian Commonwealth which guaranteed them freedom of decision not only in religious, but also in family and economic matters.

The millet system, which existed in the Ottoman Empire from the Conquest of Constantinople in 1453 until the 19th century, is often considered one of the earliest examples of non-territorial autonomy, and sometimes its most successful and long-lasting form. Some researchers have considered the millet system to be a near-ideal form of non-territorial autonomy that could be successfully applied even today, but others have in turn found that it is unsuitable for today's conditions.

The millet system was not actually a codified system, but a set of administrative practices for regulating the relations between the state and communities. Such regulations offered protection and autonomy to communities while imposing tax obligation to the state. Using the millet system, the Ottoman Empire managed the country's religious diversity, particularly regarding the Jewish, Orthodox, and Armenian communities, with smaller religious communities placed under these three larger communities in terms of state administration. Although it is generally believed that the millet system was based on religion, it has also been found that it did not concern only religious communities, but was a much more broad system of social organization and included a territorial approach in addition to a non-territorial, thereby affecting, among others, for example, the Kurds who were Muslims and lived compactly in one area.