We are pleased to share this Psychological Services special issue on clinical services and research addressing access and quality of mental health services for culturally diverse populations. Disparities in mental health services are well-known. Indeed, the extent of the vast differences in access to and quality of care resulted in the establishment by the National Institute of Mental Health’s Disparities in Mental Health Services Research Program. This introduction provides an overview of the special issue that contains current research, projects, and programs that address disparities. The articles range from literature reviews to original research and focus on a variety of historically underrepresented populations.