Disparities in mental health have persisted or worsened despite our awareness of their existence, increased understanding of their causes, and efforts at reduction and mitigation. Although much is known, there is still much to be done in mental health research to meaningfully impact disparities. In November 2020, the National Institute of Mental Health (NIMH) and the National Institute of Minority Health and Health Disparities (NIMHD) co-sponsored a virtual workshop to explore the complexities of mental health disparities, which revealed several gaps and opportunities for the field to pursue to advance mental health disparities research. This article, the introduction to a Special Issue on Mental Health Disparities, provides a frame for four articles that stem from and are inspired by the virtual NIMH/NIMHD workshop, all of which illustrate innovative research on understanding the complex mechanisms of disparities and how this knowledge can be translated into effective intervention development that advances mental health equity.