As is still the case in many parts of Iran, the distribution of languages and dialects in Ilam Province, western Iran, is unevenly documented. There have been several studies on specific language varieties spoken throughout the province but, in large part because of conflicting perspectives on the relationship between language and ethnicity, the situation for the region as a whole has until now remained unclear. The present study first of all brings together existing sociolinguistic and demographic data on language distribution and highlight areas of uncertainty. The main part of the study provides an overview of local perceptions of language distribution and language use based on field research and interviews conducted in each of the province's ten regions (shahrestān) and their twenty-five districts (bakhsh). Here, respondents' assessments of the geographic extent of the province's four main languages—Kurdish, Luri, Laki and Arabic—as well as more minor languages spoken by immigrants from elsewhere in Iran are summarized. For Kurdish in particular, which is the major of the four languages, the article shows the perceived geographic distribution of each major dialect and its affiliation within one of two major Kurdish dialect groups: Ilāmi (or “Feyli”) and Kalhōri. This analysis is followed by a brief discussion of multilingualism. The results of the study are brought together in a map of the province's languages.