Shilha ('ʃɪlhə ; from its name in Moroccan Arabic, ), now more commonly known as Tashelhiyt, Tachelhit ('tæʃəlhɪt ; from the endonym Taclḥiyt, tæʃlħijt), is a Berber language spoken in southwestern Morocco. When referring to the language, anthropologists and historians prefer the name Shilha, which is in the Oxford English Dictionary (OED). Linguists writing in English prefer Tashelhit (or a variant spelling). In French sources the language is called tachelhit, chelha or chleuh.
Shilha is spoken in an area covering around 100,000 square kilometres, making the language area approximately the size of Iceland, or the US state of Kentucky. The area comprises the western part of the High Atlas mountains and the regions to the south up to the Draa River, including the Anti-Atlas and the alluvial basin of the Souss River. The largest urban centres in the area are the coastal city of Agadir (population over 400,000) and the towns of Guelmim, Taroudant, Oulad Teima, Tiznit and Ouarzazate.
In the north and to the south, Shilha borders Arabic-speaking areas. In the northeast, roughly along the line Demnate-Zagora, there is a dialect continuum with Central Atlas Tamazight. Within the Shilha-speaking area, there are several Arabic-speaking enclaves, notably the town of Taroudant and its surroundings. Substantial Shilha-speaking migrant communities are found in most of the larger towns and cities of northern Morocco and outside Morocco in Belgium, France, Germany, Canada, the United States and Israel.
Shilha possesses a distinct and substantial literary tradition that can be traced back several centuries before the protectorate era. Many texts, written in Arabic script and dating from the late 16th century to the present, are preserved in manuscripts. A modern printed literature in Shilha has developed since the 1970s.
Shilha speakers usually refer to their language as Taclḥiyt. This name is morphologically a feminine noun, derived from masculine Aclḥiy "male speaker of Shilha".