Although the concept of resilience has been widely studied across a range of academic disciplines, examinations have typically focused upon psychosocial correlates and contributors. Fueled by progress in our understanding of the brain and complex biological processes (and recognition that domains of psychological and biological functioning are not easily dichotomized), an emerging science of neurobiological resilience has emerged. In this chapter, the authors describe extant work that has examined biological factors that may promote resilience among adversity-exposed populations and biomarkers that can serve as indicators of risk or resilience. They highlight the complexities that emerge when considering biological factors that not only operate across a range of internal bodily systems, but also interact with the multiple external systems within which an individual develops (e.g., family, school, neighborhood, etc.). They conclude with a set of principles to guide future studies and advance a more integrated resilience science.