Background and Objectives: Radicalization, a complex and multifaceted phenomenon, has been a subject of increasing concern in recent years, particularly due to its potential connection to acts of mass violence and terrorism. This systematic review examines the intricate link between radicalization and psychotic disorders, utilizing various sources such as observational studies, case reports, and series. It aims to highlight the prevalence of schizophrenia spectrum and other psychotic disorders among radicalized individuals and to define the role of mental health professionals in dealing with this issue, contributing to the development of prevention and treatment strategies. Materials and Methods: The methodology involved an extensive literature search across PubMed, Scopus, and APA PsycINFO up to 1 February 2024, adhering to PRISMA guidelines. The study focused on radicalization and psychotic disorders as defined by DSM-5 criteria, excluding other mental disorders. A population sample of 41 radicalized individuals diagnosed with psychotic disorders was selected, among which schizophrenia was identified as the predominant condition. Results: It was observed that 24% of these individuals passed away soon after committing their crimes, leading the researchers to rely on retrospective data for their diagnoses. The use of diverse assessment tools for psychiatric diagnosis and the lack of a standardized method for diagnosing or assessing involvement in the radicalization process were also noted. Despite limitations like reliance on observational studies and case reports, which result in low evidence quality and varied methodologies, our work provides a valuable contribution to clarifying the relationship between radicalization and psychotic disorders. However, further clinical studies are needed to delve deeper into these aspects. Conclusions: In conclusion, our review points out that individuals with psychotic disorders do not have a higher crime rate than the general population and warns against associating crimes with mental illness due to the stigma it creates. The lack of uniform psychiatric diagnostic tools and radicalization assessment highlights the need for more standardized risk assessment tools and validated scales in psychiatric diagnosis to better understand the relationship between radicalization and psychotic disorders and to develop integrated protocols.