This book presents a research focus on diversity and inclusivity in mathematics education. The challenge of diversity, largely in terms of student profiles or contextual features, is endemic in mathematics education, and is often argued to require differentiation as a response. Typically different curricula, text materials, task structures or pedagogies are favoured responses, but huge differences in achievement still result. If we in mathematics education seek to challenge that status quo, more research must be focussed not just on diversity but also on the inclusivity, of practices in mathematics education.