Across Europe after 1400, calls for reform echoed through the ranks of nearly every major religious order. They emerged and took root independently in ways as diverse as the late‐medieval religious and political landscape itself, yet also shared a range of common aims and characteristics. Collectively known as the Observant Movement, these efforts at reform produced some of the most important religious figures of the middle ages (Catherine of Siena and Savonarola, Bernardino of Siena and John of Capistrano, Jiménez de Cisneros, Thomas of Kempen, even the young Observant friar Martin Luther). They also reflected and inspired much that became central to late medieval religion and culture. Our textbooks, surveys and scholarly overviews long neglected the Observant story. But the last few decades of research have begun to remedy that neglect, bringing Observant reform to the center of a range of current scholarly concerns. This article surveys the emergence of that recent work, and some of its major themes: the connections between religious life and the histories of women and the laity; Observant preaching and teaching and their connection with humanism, as well as with the persecution of witches, Jews and others; the links between Observant reform and the later histories of the Reformation and the Atlantic world. It concludes with a consideration of the challenges and opportunities for future scholarship.