This book provides an in-depth examination of an important domain of development during emerging adulthood—sexuality. Emerging adulthood, which is a complex and dynamic developmental period, uniquely affords individuals a variety of choices with regard to sexuality; this volume addresses these various facets of sexuality to provide a comprehensive overview of the state of the field. The first section of the volume offers conceptualizations and foundational perspectives on sexuality in emerging adulthood, with topics including theory, developmental considerations, sexual behavior, sexual beliefs and attitudes, associations with romance, casual sex, and sexual orientation. The second section systematically examines contexts and socializing agents of sexual development, including parents, peers, media, and religion. The third section narrows in on the overarching theme of the series by addressing factors leading to flourishing and floundering in the area of sexuality during emerging adulthood, such as effects of early adversity, sexual health, sexual well-being, sexuality and mental health, and sexual assault. Accompanying seven of the chapters are brief scientific reports offering novel related research. The volume also contains four method tutorials that discuss topics in sex research such as ethical considerations, recruitment and incentive strategies, and identity-affirming methods. Concluding the volume is a chapter presenting innovative new perspectives on integration of sexual health promotion and sexual violence prevention.