Talysh (also Talishi, Taleshi or Talyshi) are an Iranian people indigenous to a region shared between Azerbaijan and Iran which spans the South Caucasus and the southwestern shore of the Caspian Sea. They speak the Talysh language, one of the Northwestern Iranian languages. It is spoken in the northern regions of the Iranian provinces of Gilan and Ardabil and the southern parts of the Republic of Azerbaijan. Northern Talysh (the part in the Republic of Azerbaijan) was historically known as Talish-i Gushtasbi. In Iran there is a Talesh County in Gilan. Anthropologically they belong to the Balkan-Caucasian type of the European race

The Talishis generally identify themselves with the ancient Cadusians, who inhabited the area to the southwest of Caspian Sea, bounded on the north by Kura River, including modern provinces of Ardabil and Zanjan. The name Talishi may be etymologically related to Cadusi, which has influenced the name of the Caspian and Caucasus.^{[citation needed]}

Talysh has two major mutually intelligible dialects — Northern (in Azerbaijan and Iran), and Southern (in Iran). According to Ethnologue, Azerbaijani is used as literary language and speakers also use Azerbaijani.