Spanish is the native language in most of Aragon, and it is the only official language, understood and spoken by virtually everyone in the region. In addition to it, the Aragonese language continues to be spoken in several local varieties in the mountainous northern counties of the Pyrenees, particularly in western Ribagorza, Sobrarbe, Jacetania and Somontano; it is enjoying a resurgence of popularity as a tool for regional identity. In the easternmost areas of Aragon, along the border with Catalonia, varieties of the Catalan language are spoken, including the comarcas of eastern Ribagorza, La Litera, Bajo Cinca, Bajo Aragón-Caspe, Bajo Aragón and Matarraña. The strip-shaped Catalan-speaking area in Aragon is often called La Franja.

The Declaration of Mequinenza (Declaració de Mequinensa in Catalan) was a document signed on February 1, 1984, in Mequinenza by the mayors of 17 municipalities of the Aragonese Catalan-speaking area together with José Bada Paniello (Minister of Culture of Government of Aragon at the time). Following the declaration, and complying with one of the proposals contained therein, on October 1, 1985, an agreement between the Government of Aragon and the Ministry of Education and Science was implemented for the teaching of the Catalan language as a voluntary and assessable subject in schools in the area.

The Languages Acts of Aragon of 2009 and 2013 have been passed to try to regulate the languages in this autonomous community. An update of these laws was announced but as of 2019 it has not been carried out.