Open Access monographs offer a real opportunity for long-form humanities and social sciences scholarship to reach a wider audience. However, unlike for journal articles, discussions around how to best achieve Open Access to books are still in a nascent stage, complicated by the large upfront costs associated with each published book. This briefing paper provides an overview of the Open Access monograph landscape, outlining the case for OA books, the costs involved, the potential for innovation, the current business models and the possible areas for policymaker intervention.