Western Isles Libraries Service manages the Western Isles Local Studies Collection in Stornoway, plus full time branch libraries in Stornoway, Tarbert, Lionacleit and Castlebay, part-time branch libraries at Shawbost and Daliburgh, and a Mobile Library Service serving rural Lewis, Harris and the Uists. Membership of the library is free to all residents of the Western Isles.

Gaelic as the mother tongue in the Western Isles plays a significant role in the literature and religious, cultural, social and educational life of the community. Western Isles Library Service aims to provide access to all aspects of Gaelic in its printed and recorded form through its branches; one copy of each book is kept in a study collection in Stornoway Library. In addition to adults' and children's books in the Gaelic language, the Library houses Gaelic periodicals, newspapers, maps, cassettes and a range of bilingual and Gaelic medium curriculum support materials for teaching staff. Gaelic language learning courses are also available, many with accompanying audio and video cassettes.