Attention-deficit/hyperactivity disorder (ADHD) is a prevalent disorder among college students. Although there is growing literature supporting the effectiveness of cognitive behavioral therapy (CBT) for this population, no previous study has investigated the feasibility of it being delivered online. In addition, recent evidence suggests that online therapy could be possible for other diagnoses such as depression, anxiety, or health-related disorders. Therefore, research in this area could be critical, as online settings could also improve accessibility to evidence-based interventions for college students with ADHD. This study describes the implementation of CBT for ADHD intervention delivered online for two college students with this diagnosis. We found improvements in both self-reported and clinician-assessed outcomes, in measuring ADHD-related behaviors, executive functioning, emotional comorbidities, and quality of life. These changes were more evident in the case that was more severe at pre-treatment, and were maintained at a 6-month follow-up; even further improvements in self-reported quality of life were observed. These findings support the potential feasibility and clinical utility of online CBT in this population.