Overview
An unincorporated area is a region that is not governed by a local municipal corporation. There are many unincorporated communities and areas in the United States and Canada. Most other countries have very few or no unincorporated areas.
By country
Argentina
In Argentina, the provinces of Chubut, Córdoba, Entre Ríos, Formosa, Neuquén, Río Negro, San Luis, Santa Cruz, Santiago del Estero, Tierra del Fuego, and Tucumán have areas that are outside any municipality or commune.
Australia
Unlike many other countries, Australia has only one level of local government immediately beneath state and territorial governments. A local government area (LGA) often contains several towns and even entire metropolitan areas. Thus, aside from very sparsely populated areas and a few other special cases, almost all of Australia is part of an LGA. Unincorporated areas are often in remote locations, cover vast areas, or have very small populations.
From Wikipedia (CC BY-SA 4.0).