This article looks at the possible implications of Brexit for approaches to open access (OA) in the UK. It begins by sketching current issues in Brexit debates at the end of 2016 as the context into which discussions about open access are then placed. Issues in four thematic areas are analysed: OA policies and mandates, EU copyright reform, new OA publishing models and open science. The level of dependence in the UK on European developments is assessed in each case and its contribution to Brexit issues identified. The paper concludes that Brexit presents not only challenges, but also opportunities which the UK could seize. In open access, the UK is already playing a leadership role. In areas of open science, particularly in relation to the European Open Science Cloud, it is the European Commission which is asserting leadership. The UK needs to consolidate its current activity and ensure that, whatever the nature of Brexit arrangements, its freedom does not lead to isolation.