The Leonese are an ethnic group whose homeland is the former Kingdom of León, now known as region of Leon. This area was formerly a country in Southwestern Europe that covered a territory in northwestern Spain and northeastern Portugal.

The Leonese Kingdom was an independent kingdom in the Middle Ages, keeping its status as a kingdom under the Spanish rule until the 1833 territorial division of Spain. The languages of León are the Leonese language and Spanish in Spain and the Leonese and Portuguese in Portugal.

A variety of Leonese called Mirandese (mirandês) is spoken in the Miranda do Douro Region of Portugal.

There are Leonese minorities in the District of Bragança (Portugal) that maintain Leonese culture and Leonese language, mainly in the northwest (Riodonor, Guadramil) and in the Land of Miranda, where a Leonesedialect known as Mirandês was officially recognised by the Parliament of Portugal.

The Leonese language developed from Vulgar Latin with contributions from the pre-Roman languages spoken in the Spanish provinces of León, Zamora, and Salamanca and in some villages in the District of Bragança, Portugal. Close to Mirandese and Asturian or Bable, it belongs to the Astur-Leonese subgroup of Iberian languages.

Leonese was the official language of the Leonese Kingdom in the Middle Ages and achieved a high codification grade. The first written text in Leonese was Nodicia de Kesos (959 or 974).

Its precarious situation as a minority language has driven Leonese to near extinction; it is considered a seriously endangered language by UNESCO. There are ongoing language revival efforts to try to get the urban population interested in the language. There is the Leonese Council that promotes the language, and the municipalities of Zamora, Coyanza, Mansilla de las Mulas or La Bañeza have promoted the teaching of Leonese.