This article examines professional diviners employed by the Qing (1636–1912) government to assist in local administration. Known as yin-yang officers, these officials served among the technical and religious specialists embedded in prefectural and county governments across the empire. Although they held marginal or unranked positions within the formal bureaucracy, yin-yang officers played a vital role in both administrative and ritual life at the grassroots level. By tracing their training, sources of authority, and everyday responsibilities, this article sheds light on the Qing’s local technical and religious bureaucracy—an often-overlooked dimension of imperial statecraft that bridged ritual, cosmological knowledge, healing and divination, and official governance. It argues for the importance of examining imperial bureaucracy from below, showing how these unsalaried, low-level figures helped sustain the empire’s overstretched administrative apparatus well into the early twentieth century.