ObjectiveTo examine the extent, nature and quality of literature on the impact of the COVID-19 pandemic on the mental health of imprisoned people and prison staff.DesignScoping review.Data sourcesPubMed, Embase, CINAHL, Global Health, Cochrane, PsycINFO, PsychExtra, Web of Science and Scopus were searched for any paper from 2019 onwards that focused on the mental health impact of COVID-19 on imprisoned people and prison staff. A grey literature search focused on international and government sources and professional bodies representing healthcare, public health and prison staff was also performed. We also performed hand searching of the reference lists of included studies.Eligibility criteria for selection of studiesAll papers, regardless of study design, were included if they examined the mental health of imprisoned people or prison staff specifically during the COVID-19 pandemic. Imprisoned people could be of any age and from any countries. All languages were included. Two independent reviewers quality assessed appropriate papers.ResultsOf 647 articles found, 83 were eligible for inclusion, the majority (58%) of which were opinion pieces. The articles focused on the challenges to prisoner mental health. Fear of COVID-19, the impact of isolation, discontinuation of prison visits and reduced mental health services were all likely to have an adverse effect on the mental well-being of imprisoned people. The limited research and poor quality of articles included mean that the findings are not conclusive. However, they suggest a significant adverse impact on the mental health and well-being of those who live and work in prisons.ConclusionsIt is key to address the mental health impacts of the pandemic on people who live and work in prisons. These findings are discussed in terms of implications for getting the balance between infection control imperatives and the fundamental human rights of prison populations.