Diversity in its many guises is strongly championed in the adult education literature. To conceive a future for adult education that is not diverse and does not try to address the needs of diverse learners seems absurd. Yet, diversity is not a unitary concept, having many definitions and paradoxical effects. Questions arise about its future in a globalizing world. It is not obvious that all facets of diversity in adult education can thrive into the future. This paper attempts to explore the future of diversity in adult education. It applies two methodologies used in futures research to do so. One, causal layered analysis (CLA), enables the present to be analysed critically in order to explore possible futures. In this paper CLA is used to identify possible effects of globalization on diversity in adult education. The other methodology used is visioning. The adult education literature is examined for its visions of diversity. Four different visions are identified. Each theorizes diversity differently. One aims for individual personal development within an accommodating, non-critical context. A second emphasizes personal development but within a context that is critical, striving for a more just society. A third envisions social learning facilitating change towards a critical, more just society. A fourth focuses on social learning but within an accommodating, non-critical context. CLA and visioning enable some tentative statements to be made about the future of diversity in adult education. Chief among them is that diversity, when valued in the market place, will prosper, while diversity that is intended to act as an agent for social change will not.