Over the last few decades, clinical psychologists have played a key role in the development of empirically-validated psychosocial interventions for those with serious mental illness (SMI). However, in contrast to these substantial contributions, clinical psychologists in the United States are grossly underrepresented in treatment provision with this population (Roe, Yanos, & Lysaker, 2006; Rollins & Bond, 2001). This review aims to highlight various factors contributing to the establishment and perpetuation of this underrepresentation. First, we highlight systemic factors (e.g., the emergence of managed care) through an examination of the evolving role of the clinical psychologist. Next, we review training-based factors (e.g., limitations to SMI specific training) through a review of training in clinical psychology. Through an examination of training factors, the role of mental health stigma amongst clinicians toward individuals with SMI is identified as a potential perpetuating factor of this underrepresentation. Factors associated with clinician stigma are then reviewed and the relationship between clinical training and clinician stigma is considered. Lastly, important future directions to further investigate and address this underrepresentation are suggested – namely, investigating factors (training and individual) that may impact clinical psychology doctoral students' attitudes toward those with SMI. •Psychologists are underrepresented in work with serious mental illness.•Systemic (e.g., managed care) factors contribute to this underrepresentation.•Training factors (e.g., limited faculty expertise) may also contribute.•Further, stigma held amongst psychologists may perpetuate this issue.