The Mirandese language (autonym: mirandés or lhéngua mirandesa; Portuguese: mirandês or língua mirandesa) is a Romance language belonging to the Astur-Leonese linguistic group, sparsely spoken in a small area of northeastern Portugal, in the municipalities of Miranda do Douro, Mogadouro and Vimioso. The Portuguese Parliament granted it co-official recognition (along with the Portuguese language) for local matters on 17 September 1998 with the law 7/99 of 29 January 1999.

Mirandese has a distinct phonology, morphology and syntax, and has been distinct at least since the formation of Portugal in the 12th century.^{[citation needed]} It has its roots in the spoken Latin of the north of the Iberian Peninsula (Portuguese developed in the northwest).

It is a descendant of the ancient Astur-Leonese language of northern Iberia, the last remnant of the ancient language of the Kingdom of León, and closely related to the modern Astur-Leonese languages in Spain. However, these amalgamations in the Spanish territory did not affect Mirandese, which preserves distinct linguistic differences in relation to both Portuguese and Spanish. It shares a great deal of lexicon with regional Portuguese dialects.