This article evaluates the design, delivery, and main outcomes of Cardiff University's first "Massive Open Online Course" (MOOC) entitled "Muslims in Britain: Changes and Challenges," delivered to over 20,899 international learners between 2014 and 2019. I explore the design principles underpinning the course and offer a detailed quantitative overview of our learner-base. The paper examines the experience of course delivery, as well as providing an evaluation of the outcomes arising from the course in the short, medium and long-term. It also explores some of the distinctive aspects of learning about religion (and Islam, in particular) online as a result of our course, thereby contributing to discussion about the pedagogy of Religious Studies in the digital environment.