The goal of this study is to explore the status quo of mental health and substance use problems among older prisoners. Our review presents the prevalence as well as co-occurrence of substance use and other mental health disorders in older prisoners. We conducted a systematic review of literature following the PRISMA statement. The search was carried out in four databases and supplemented with manual screenings of bibliographies from all retrieved articles. Publications were included if they met specific inclusion criteria. A total of 17 articles were included and in half of them, older offenders were the main study population. Older inmates have higher prevalence of mental health disorders than younger prisoners and are more likely to use alcohol. Several studies mentioned an association between substance use and other mental health disorders. Access to treatment was a concern with several studies providing recommendations to improve this. Most studies were done on older male prisoners, confirming that older female prisoners constitute a subgroup of a subgroup which is even more vulnerable and under-researched. It is important to carry out more research on both older male and female prisoners to ensure optimal delivery of appropriate mental health care for older prisoners and to prepare for a currently younger population that will age with different and distinct mental health problems and substance use patterns.