This article centers on the life of Bilal Ould Mahmoud, an enslaved man who became a spiritual authority in the nineteenth-century Sahara. It examines how Bilal's piety allowed him to rise to prominence in a hierarchical context that subjugated him to an inferior position. Yet what makes him so fascinating to study is his ability to achieve the highest station as a Sufi saint without being attached to a Sufi order. Using Bilal's case, this article makes two important contributions to the historiographies of Sufism and slavery. First, it brings fresh perspectives to the studies of Sufism outside of ṭarīqa (Sufi orders). Second, it contributes to the studies of Saharan slavery by exploring enslaved Muslims’ experiences beyond the practice of illicit magic, and also as part of how they exercised their saintly authority as empowered agents. In the process, it analyzes the interplay among Islam, race, and slavery in the nineteenth-century Sahara.