The word comes from French "premier ministre" which means prime minister. "Premier" meaning "first", coming from Latin prīmārius. This is why in many nations, "premier" is used interchangeably with "prime minister".
In five of the British overseas territories (Bermuda, the Cayman Islands, Montserrat, the Turks and Caicos Islands, and the British Virgin Islands), the elected heads of government are styled as "Premier". In other overseas territories the equivalent post is styled as Chief Minister.
"Premier" is also the title of the heads of government in sub-national entities, such as the provinces and territories of Canada, states of the Commonwealth of Australia, provinces of South Africa, the island of Nevis within the Federation of Saint Kitts and Nevis, and the nation of Niue. In some of these cases, the formal title remains "Prime Minister" but "Premier" is used to avoid confusion with the national leader. In these cases, care should be taken not to confuse the title of "premier" with "prime minister". In these countries, terms such as "Federal Premier", "National Premier" or "Premier of the Dominion" were sometimes used to refer to prime ministers, although these are now obsolete. In Cambodia, "Premier" means the "Prime Minister". In Federation of Bosnia and Herzegovina, sub-national entity of Bosnia and Herzegovina, as well in cantons, head of government have formal title of "premier", often anglicized as "prime minister", while national prime minister is , but "premier" is sometimes colloquially used.
In Croatia, the head of government is officially called "President of the Government" (predsjednik vlade) but "Premier" (premijer) is colloquially used.
In Serbia, the head of government is officially called "President of the Government" (predsednik vlade) but "Premier" (premijer) is colloquially used.
In Poland, the head of government is officially called "President of the Council of Ministers" (Polish: Prezes Rady Ministrów, lit. 'Chairman of the Council of Ministers') but "Premier" (polish for Prime Minister) is colloquially used.
A premier will normally be a head of government, but is not the head of state. In presidential systems, the two roles are often combined into one, whereas in parliamentary systems of government the two are usually kept separate.
In the Soviet Union, the title of premier was applied to the Chairman of the Council of People's Commissars, named Chairman of the Council of Ministers after 1946, which became the Prime Minister of the Soviet Union in 1991.