Activities that actively and deliberately support museum visitors’ engagement with art and promote learning occupy a distinct, though contested, place in the history and current framing of the art museum across the globe. Despite its many benefits, educational work in art museums has grown erratically, frequently without formal structures, systems, or strategies, and it has been critiqued in the past for lacking a robust theoretical framework and consistent methodological principles. It remains the case that the field is broad, diverse, and continually evolving; in the early 21st century, the boundaries are shifting, for example, between what constitutes curatorial practice and learning practice in contemporary art museums. This fluidity and heterogeneity has enabled the emergence of creative and responsive practice that encourages visitors to learn with, through, and about art, but it poses challenges when the goal is to present a coherent overview. Therefore any summary of this complex domain will necessarily be selective. Nonetheless, taking the practice as it has been developed in the United Kingdom and the United States, where this work has been theorized and communicated to the greatest extent (and with reference to the practice in Europe, Canada, and Australia), it is possible to identify common historical developments, shared philosophical and pedagogical principles, and collective challenges and opportunities that contribute to a comprehensible picture, albeit one that is replete with contradictions. As a field, art-museum education continues to define itself. And although valuable research and theorization have been undertaken, in part by practitioners drawing on their own experiences, further work is required, not least to broaden the understanding of the practice as it is manifest globally and to make explicit the increasingly important role of art education within the art museum.