ABSTRACT Research suggests that autistic individuals have qualitatively unique experiences of prison social environments, and that these experiences may have implications for autistic prisoners’ mental wellbeing and engagement with offending behaviour interventions. However, this has yet to be quantitatively tested. Using a sample of 177 adult prisoners from two UK prisons that exclusively house individuals with sexual convictions, this study tested a hypothesised double-mediation model, to investigate associations between autistic traits and prisoners’ readiness to engage with treatment, and whether this was mediated by experiences of the prison social climate and mental wellbeing. Results indicated that prisoners with higher levels of autistic traits had poorer experiences of prison social climates, which, in turn, predicted higher levels of anxiety and depression, which subsequently predicted reduced level readiness to engage with offending behaviour interventions. Implications for research and practice are discussed, emphasising the need for increased autism-related awareness and support provisions in prisons. PRACTICE IMPACT STATEMENT The present study is a novel quantitative study, which is the first to statistically demonstrate that neurodivergence can significantly influence prisoners’ perceptions of prison social climates, mental wellbeing, and ultimately readiness to engage with rehabilitate interventions. As such, these findings emphasise the importance of embedding understanding neurodiversity in prison staff training, as well as considering and accommodating neurodiversity as a key dimension in the development of a prison’s rehabilitative culture.