Despite comprising the largest proportion of the “lesbian, gay, and bisexual” population, research focusing on the unique health concerns and needs of bisexual individuals is relatively scarce. While health disparities are increasingly well documented among lesbian, gay, bisexual, and transgender individuals relative to their heterosexual and cisgender counterparts, gaps remain in our basic understanding of how health status, behaviors, and outcomes vary within these groups, especially bisexual individuals. The lack of specified research on bisexual health is even more curious given that, when separated from both heterosexual and gay/lesbian individuals, bisexual individuals consistently report higher rates of a wide range of negative health outcomes, including mood and anxiety disorders, substance use, suicidality, as well as disparities related to healthcare access and utilization. Indeed, in scientific research, mass media, and in public health interventions, bisexual individuals remain relatively invisible. This Special Section represents an effort to shed light on a new generation of quantitative, qualitative, and mixed methods research studies that examine health-related concerns, outcomes, and intervention opportunities specifically among diverse samples of bisexual individuals from a variety of social and cultural contexts. The research herein focuses on intersections of multiple identities, the development of new measures, the use of large national data sets, and diverse groups of self-identified bisexual men (who tend to be least visible in health research). Findings from these studies will significantly advance our knowledge of factors associated with health disparities, as well as health and well-being more generally, among bisexual individuals and will help to inform directions for future health promotion research and intervention efforts.