Eating disorders and attention deficit/hyperactivity disorder (ADHD) are highly comorbid. The majority of research on this comorbidity has focused on impulsivity, which is a shared vulnerability between ADHD and eating disorders characterized by binge eating. Less is known about which shared factors may contribute to the co-occurrence of other eating disorders (i.e., anorexia nervosa, restricting subtype) and ADHD. Furthermore, little research has focused on other potential overlapping vulnerabilities, though deficits in emotion regulation have been implicated as an additional shared vulnerability. The current study (N = 306 undergraduate students) uses path analysis to examine if emotion regulation difficulties and negative urgency (i.e., impulsivity during negative mood state) are unique or shared vulnerabilities for ADHD symptoms (inattention, hyperactivity-impulsivity) and eating disorder symptoms (bulimic symptoms, drive for thinness). Emotion regulation difficulties were uniquely associated with all dimensions of ADHD and eating disorder symptoms, and negative urgency was uniquely associated with global eating disorder symptoms, bulimic symptoms, and drive for thinness. These results suggest that emotion regulation difficulties are a shared vulnerability factor for the development of diverse presentations of ADHD and eating disorder symptoms, and may be an important prevention target. Additionally, our results support a unique relationship between negative urgency and drive for thinness. Future research should examine these associations prospectively and experimentally to determine directionality and inform preventative interventions for ADHD and eating disorders.