Biosocial criminology is a multidisciplinary perspective that attempts to understand the causes and consequences of criminal behavior and related outcomes. Biosocial criminologists employ methods from a variety of disciplines, including genetics, psychophysiology, neuroscience, sociology, and psychology. For years, biosocial criminology struggled to gain traction within the field of criminology. Although some resistance among criminologists remains, biosocial criminology is starting to become more firmly established as an important subdivision within criminology. Demonstrating this, at the 2019 Annual Meeting of the American Society of Criminology (ASC), there were 27 oral sessions listed in the online preliminary program under the keyword, "Biosocial or Genetic Factors." For comparison, there were 31 oral sessions listed under the keyword, "Strain/learning/control" (ASC, 2019). This is a small difference, given that strain, learning, and control are major theoretical frameworks in criminology. In addition to the growing number of biosocial themed panels, the ASC Division of Biopsychosocial Criminology was established in 2017, representing a further step toward establishing the legitimacy of the discipline within the field. For many years, biosocial criminologists have been forced to expend considerable time and effort justifying the importance of studying crime from a biosocial perspective. Fortunately, given their growing acceptance, biosocial criminologists will increasingly be required to spend less time justifying the discipline's need to exist. This opens the door to dramatically advance the state of the science and knowledge in the field. The articles in this special issue do just that.