This article examines James Boswell’s still-unpublished “Dictionary of the Scots Language,” contextualizing it within eighteenth-century debates about Scots and emphasizing the ways that it diverges from the work of Boswell’s peers. While Samuel Johnson’s dictionary follows literary precedent, and the work of the Scottish literati encourages readers to minimize the Scottishness of their speech and writing, Boswell’s dictionary features a surprisingly familiar and conversational form of the Scots language. As such, the dictionary both highlights Boswell’s own interest in the vernacular and points to an alternative thread in eighteenth-century thinking about Scots.