Occitan, also known as lenga d'òc by its native speakers, sometimes also referred to as Provençal, is a Romance language spoken in Southern France, Monaco, Italy's Occitan Valleys, as well as Spain's Val d'Aran in Catalonia; collectively, these regions are sometimes referred to as Occitania. It is also spoken in Calabria in a linguistic enclave of Cosenza area. Some include Catalan in Occitan, as the distance between this language and some Occitan dialects is similar to the distance between different Occitan dialects. Catalan was considered a dialect of Occitan until the end of the 19th century and still today remains its closest relative.

Catalan, known in the Valencian Community and Carche as Valencian, is a Western Romance language. It is the official language of Andorra, and an official language of three autonomous communities in eastern Spain: Catalonia, the Balearic Islands and the Valencian Community, where it is called Valencian. It has semi-official status in the Italian comune of Alghero, and it is spoken in the Pyrénées-Orientales department of France and in two further areas in eastern Spain: the eastern strip of Aragon and the Carche area in the Region of Murcia. The Catalan-speaking territories are often called the Països Catalans or "Catalan Countries".