The lifetime prevalence of Bipolar II is 0.4% with the time spent with depressive symptoms outnumbering the time spent with hypomanic symptoms by 35 to 1. Regarding current treatment options, psychotherapy is effective for managing depressive symptoms, with CBT being particularly efficacious. Unfortunately, CBT is often not a feasible treatment option. Electronic CBT (e-CBT) is more accessible for treating various mental illnesses with evidence suggesting it can increase treatment adherence and patient satisfaction. Moreover, e-CBT is suggested to have comparable outcomes to in-person CBT in the treatment of depression and anxiety. Typically, patient-clinician interactions of e-CBT are administered through email however, this is an insecure, unsustainable, and non-scalable treatment delivery method. The proposed study will use the Online Psychotherapy Tool (OPTT), a secure cloud-based platform for the delivery of e-CBT. The aim is to evaluate the feasibility and effectiveness of using OPTT for the treatment of BAD-II with depressive symptoms, while also analyzing social, cultural, and personal factors affecting patients' experience. Participants (n = 80) diagnosed with BAD-II in a depressive episode will be recruited from the Mood and Anxiety Clinic at Providence Care Hospital in Kingston, Ontario, Canada. Eligible participants will then be randomly assigned to either the treatment group (e-CBT plus treatment as usual (TAU)) (n = 40) or the control group (TAU) (n = 40) where they will complete the 12-week program. Participants in the TAU group will be offered the e-CBT program after the first 12 weeks if they wish to take part. Participants in the e-CBT group will complete weekly modules mirroring in-person CBT content and complete homework assignments that will be evaluated by a clinician who will provide personalized feedback through OPTT. Progression/regression of participants will be analyzed using the MADRS, YMRS, and CGI-BP-M questionnaires administered at baseline, after week 6, and after week 12. Personal, social, and cultural factors impacting participant experience will be investigated through an in-depth interview utilizing focus groups. The findings from this study will be the first on the effectiveness of delivering e-CBT to patients with BAD-II with residual depressive symptoms. This approach can provide an innovative method to address the barriers associated with in-person psychotherapy.