Emotion dysregulation is a pattern of emotional experience or expression that interferes with goal-directed behavior, and may set children and adolescents on developmental trajectories toward psychopathology. Despite accumulating evidence linking emotion dysregulation to various forms of internalizing psychopathology (e.g., depression, anxiety), several open questions remain. What are the developmental pathways leading to emotion dysregulation and modifiable environmental conditions that appear to foster it? What is the evidence that emotion dysregulation precedes or plays a causal role in the development of internalizing spectrum disorders? What are the biological underpinnings of emotion dysregulation, and how can we integrate this research with recent discoveries about internalizing spectrum disorders from neuroscience, psychophysiology, genetics, and epigenetics? This review discusses recent research pertinent to these three primary questions and concludes with suggestions for future research and implications for interventions that promote resilience in youth.