The Knights of Labor became one of the great global working-class movements of the nineteenth century between 1880 and 1900, extending from New Zealand to Belgium, Scotland to South Africa. That story, however, has been told only in fragments, on local, regional, and national levels. No truly global history of the Knights of Labor yet exists. This article brings together what historians have so far uncovered of their activities outside Canada and the United States, provides an outline of what their global history might look like, and shows how that history enriches our understanding of national labor histories across the world and of the Knights themselves in their American home. Finally, this article addresses the wide range of historical topics that would benefit from such a global history, including labor and imperial history and the construction of gender and color lines on an international scale during the nineteenth century.