A county, abbreviated Cnty. (US) or Co. (UK and Ireland), is a geographical region of a country used for administrative or other purposes, in certain modern nations. The term is derived from the Old French conté or cunté denoting a jurisdiction under the sovereignty of a count (earl) or a viscount. The modern French is comté, and its equivalents in other languages are contea, contado, comtat, condado, Grafschaft, graafschap, Gau, etc. (cf. conte, comte, conde, Graf).

When the Normans conquered England, they brought the term with them. The Saxons had already established the districts that became the historic counties of England, calling them shires (many county names derive from the name of the county town with the word "shire" added on: for example, Gloucestershire and Worcestershire). The Vikings introduced the term earl (from Old Norse, jarl) to the British Isles. Thus, "earl" and "earldom" were taken as equivalent to the continental use of "count" and "county". So the later-imported term became a synonym for the native English word scir ([ʃiːr]) or, in Modern English, shire. Since a shire was an administrative division of the kingdom, the term "county" evolved to designate an administrative division of national government in most modern uses.

A powiat (pronounced [ˈpɔvʲat]; Polish plural: powiaty) is the second-level unit of local government and administration in Poland, equivalent to a county, district or prefecture (LAU-1, formerly NUTS-4) in other countries. The term "powiat" is most often translated into English as "county".

A powiat is part of a larger unit, the voivodeship (Polish województwo) or province.

A powiat is usually subdivided into gminas (in English, often referred to as "communes" or "municipalities"). Major towns and cities, however, function as separate counties in their own right, without subdivision into gminas. They are termed "city counties" (powiaty grodzkie or, more formally, miasta na prawach powiatu) and have roughly the same status as former county boroughs in the UK. The other type of powiats are termed "land counties" (powiaty ziemskie).

As of 2008, there were 379 powiat-level entities: 314 land counties, and 65 city counties. For a complete alphabetical listing, see "List of Polish counties". For tables of counties by voivodeship, see the articles on the individual voivodeships (e.g., Greater Poland Voivodeship).

The counties of Sweden (Swedish: län) are the top-level geographic subdivisions of Sweden. Sweden is today divided into 21 counties; however, the numbers of counties has varied over time, due to territorial gains/losses and to divisions and/or mergers of existing counties. This level of administrative unit was first established in the 1634 Instrument of Government on Lord Chancellor Count Axel Oxenstierna's initiative, and superseded the historical provinces of Sweden (Swedish: landskap) in order to introduce a more efficient administration of the realm. At that time, they were what the translation of län into English literally means: fiefdoms. The county borders often follow the provincial borders, but the Crown often chose to make slight relocations to suit its purposes.

In every county except Gotland there is a county administrative board (länsstyrelse) headed by a governor (landshövding), appointed by the government, as well as a separate county council (landsting).