BackgroundCancer survivors are vulnerable to experiencing symptoms of anxiety and depression and may benefit from accessible interventions focused on improving emotion regulation. CanCope Mind (CM) was developed as an internet-delivered intervention adapted from the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders to improve emotion regulation and support the mental health of cancer survivors.ObjectiveThis protocol aims to provide an outline of the CanCope Study, a trial comparing the efficacy of a Unified Protocol–adapted internet-delivered intervention (CM) designed for cancer survivors compared with an active control condition—an internet-delivered healthy lifestyle intervention, CanCope Lifestyle (CL). The primary aim is to assess and compare the efficacy of both interventions in improving emotion regulation, anxiety and depressive symptoms, and quality of life. The secondary aims involve assessing the mechanisms of the CM intervention.MethodsThis trial is a 2-arm randomized controlled trial that allocates cancer survivors to either CM or CL. Both interventions comprise 4 web-based modules and are expected to take participants at least 8 weeks to complete. Participants’ mental and physical health will be assessed via self-reported surveys at baseline (T0), between each module (T1, T2, and T3), immediately after the intervention (T4), and at 3-month follow-up (T5). The study aims to recruit 110 participants who have completed T4.ResultsThe CanCope study began recruitment in September 2020. A total of 224 participants have been randomized to the CM (n=110, 49.1%) and CL (n=114, 50.9%) groups.ConclusionsThis is one of the first trials to develop and investigate the efficacy of a web-based intervention for cancer survivors that specifically targets emotion regulation.Trial RegistrationAustralian Clinical Trials ACTRN12620000943943; https://tinyurl.com/b3z9cjspInternational Registered Report Identifier (IRRID)DERR1-10.2196/36658