Recent years have seen the incorporation of telepsychology into poorly accessed, rural, and underserved settings, including criminal justice and substance abuse treatment. A systematic search of the literature on telepsychological and related services with justice-involved and substance abuse clients revealed numerous descriptive reports, but few empirical studies. The results of 3 studies of criminal justice participants and 2 studies of substance-abuse participants were subjected to a series of 5 outcome-specific meta-analyses (mental health symptoms, therapeutic processes, program engagement, program performance, and service satisfaction). These 5 studies, all of which utilized a comparison group, contributed a total of 342 participants and 14 total effect sizes. Summary data on 3 additional uncontrolled studies are also presented. Results indicated that telepsychological outcomes were at least comparable with in-person outcomes. This review serves as an initial reference for clinicians and policymakers working with criminal justice and substance abuse clients, but also highlights the need for more rigorous scientific investigation into the nuances of telepsychological practice.