A unitary authority is a type of local authority that has a single tier and is responsible for all local government functions within its area or performs additional functions which elsewhere in the relevant country are usually performed by national government or a higher level of sub-national government.
Typically unitary authorities cover towns or cities which are large enough to function independently of county or other regional administration. Sometimes they consist of national sub-divisions which are distinguished from others in the same country by having no lower level of administration.
In Canada, each province creates its own system of local government, so terminology varies substantially.
In certain provinces (e.g. Alberta, Nova Scotia) there is only one level of local government in that province, so no special term is used to describe the situation.
British Columbia has only one such municipality, Northern Rockies Regional Municipality, which was established in 2009.
In Ontario the term single-tier municipalities is used, for a similar concept. Their character varies, and while most function as cities with no upper level of government, some function as counties or regional municipalities with no lower municipal subdivisions below them. They exist as individual census divisions, as well as separated municipalities.
In Germany, kreisfreie Stadt (literally circle-free city) is the equivalent term for a city with the competences of both the Gemeinde (municipality) and the Kreis (district, literally circle) administrative level. The directly elected chief executive officer of a kreisfreie Stadt is called Oberbürgermeister (literally Superior Burgomaster, in English "Chief Mayor" or "Lord Mayor"). The British counties have no directly corresponding counterpart in Germany. This German system corresponds to statutory cities in Austria and in the Czech Republic.