Iran is home to a treasury of languages representing diverse language families: Iranic, Turkic, Semitic, Indic, Dravidian, Armenian, and Kartvelian, as well as sign languages. Despite valuable research carried out by Iranian and western scholars, there is still no comprehensive publication depicting the geographic distribution and linguistic status of language varieties in Iran. In order to work toward this goal, the Atlas of the Languages of Iran (ALI) (www.iranatlas.net) was officially launched in 2015 as an international, online research programme. The present study opens with a historical overview of the research context and underlines the ongoing necessity of constructing such an atlas for the languages of Iran. The article then outlines the design of the Atlas, the methodology necessary to guide and organize the research project, and the results which are being generated. Specifically, we look at the Atlas bibliography, classification of Iran’s languages, the design of a set of linguistic data questionnaires, and findings from fieldwork. Selected initial research results from fieldwork in Chahar Mahal va Bakhtiari and Hormozgan Provinces, where the research process is most advanced, are provided in the form of linguistic data maps.