Circumpolar regions face unique challenges in establishing and maintaining mental health care systems, including forensic psychiatry services. The scarcity of data and lack of evidence concerning the forensic psychiatry patient (FPP) populations of Nunavut and Greenland exacerbates the challenges of informing best practices and healthcare planning. By comparing the prevalence of forensic psychiatry patients, the mental health care services, and the legislation in these two relatively similar but unique regions, insight may be gained that can help inform healthcare planning. This cross-sectional study includes all forensic psychiatry in- and outpatients in one year from Nunavut (2018) and on February 29, 2020, in Greenland. The Greenland sample (n = 93) was nearly four times larger than the Nunavut sample (n = 15) at the population level. Despite considerable differences in forensic legislation and service supply, the forensic psychiatry patients in the two areas share several similarities. A total of 87% (n = 13) in the Nunavut sample were diagnosed with a DSM-5 schizophrenia spectrum disorder or other psychotic disorder. In Greenland, 82% (n = 76) were diagnosed with an ICD-10 F2 diagnosis (schizophrenia, schizotypal and delusional disorders). Approximately 2/3 of the patients in both populations were diagnosed with substance use disorder, and 60% of the Nunavut FPP received long-acting antipsychotic injections versus 62% in Greenland. Nearly half of the FPPs in both populations had never been convicted prior to entering the forensic psychiatry system; Nunavut 45% versus Greenland 47%. A substantial proportion of Greenlandic FPPs were outpatients compared to Nunavut (83% versus 47%). This study is an essential first step toward describing a Model of Care for forensic psychiatry patients in circumpolar regions; furthermore, the clinical similarities between the two populations provide support for future joint Arctic research and the inclusion of artic forensic patients in international studies.Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.