This paper presents the first comprehensive checklist of the non-marine molluscs from the western Himalaya, a region of high biodiversity and endemism. Based on faunistic surveys during 2019-2023 and published records, the paper reports 242 species belonging to 101 genera and 45 families of gastropods and bivalves, of which 168 species are endemic to the region. The paper also provides new distribution records and taxonomic notes for some species. Among the notable findings are the first records of Limax mayae, Oxyloma sp., Odhneripisidium kuiperi, Thiara aspera from India, and Bensonies jamuensis, Euaustenia cassida, Stagnicola sp. from the western Himalaya. The paper presents some species with substitutional illustrations and literature from the region for the past two centuries. Additionally, the paper also discusses the threats that non-marine molluscs face in the western Himalaya and suggests some conservation measures to protect them. The authors hope this paper will serve as a baseline for future studies on the diversity, distribution, ecology, and conservation of non-marine molluscs in the western Himalaya.