A municipiu (from Latin municipium; English: municipality) is a level of administrative subdivision in Romania and Moldova, roughly equivalent to city in some English-speaking countries.

In Romania, this status is given to towns that are large and urbanized; at present, there are 103 municipii. There is no clear benchmark regarding the status of municipiu even though it applies to localities which have a sizeable population, usually above 15,000, and extensive urban infrastructure. Localities that do not meet these loose guidelines are classified only as towns (orașe), or if they are not urban areas, as communes (comune). Cities are governed by a mayor and local council. There are no official administrative subdivisions of cities even though, unofficially, municipalities may be divided into quarters/districts (cartiere in Romanian). The exception to this is Bucharest, which has a status similar to that of a county, and is officially subdivided into six administrative sectors.

In Moldova, which has thirteen municipii, a 2002 law provides that the status applies to the cities that play an important role in the country's economic, social, cultural, scientific, political and administrative life.