Objective: Anxiety and depression are highly prevalent in people with epilepsy (PWE) and contribute to increased disability. Unfortunately, there are numerous barriers (e.g., cost, distance, and stigma) and service gaps (e.g., lack of services and trained clinicians) that prevent many PWE from accessing traditional face-to-face psychological services. The aim of the present study was to examine the feasibility of a new transdiagnostic Internet-delivered cognitive behavioral therapy (iCBT) program, the Chronic Conditions Course, to simultaneously treat symptoms of anxiety, depression, and disability. Methods: A single-group feasibility open trial was employed involving 27 adults with epilepsy. The program comprises five online lessons delivered over 8 weeks and is provided with weekly contact from a mental health professional via e-mail and telephone. Results: High treatment completion rates and levels of satisfaction were reported. Evidence of significant improvements in our primary outcomes (within-group Cohen's d [d]; average [avg.] reductions) of anxiety (d ≥ 1.28; avg. reduction ≥ 54%), depression (d ≥ 1.24; avg. reduction ≥ 54%), epilepsy-specific depression (d ≥ 0.95; avg. reduction ≥ 35%), and disability (d ≥ 0.62; avg. reduction ≥ 33%) were observed at posttreatment, which were sustained at or further improved to 3-month follow-up. On our secondary outcomes there were significant improvements for life satisfaction (d ≥ 0.70; avg. improvement ≥ 26%) but not for perceived cognitive difficulties (d ≥ 0.48; avg. reduction ≥ 15%). Highlighting the potential of the approach, relatively little clinician time was required per participant (mean 80.62 min, standard deviation [SD] 54.78), and the trial involved a broad range of geographically dispersed patients. Significance: The findings of the current study support the feasibility and potential of transdiagnostic Internet-delivered treatments for adults with epilepsy. Further large-scale controlled trials are warranted. ; 10 page(s)