Adolescents and young adults (AYA) diagnosed with cancer experience unique challenges after completing treatment and face distinct barriers to optimal care and support. These challenges include higher levels of symptom burden and treatment complications, interrupted education, careers and relationships, and financial hardship. AYA lack access to peers, relevant information and emotional support, and report gaps in care when dealing with these difficult challenges. Digital peer navigation could help to address the needs of AYA and overcome barriers to care and support. The PI developed True North Peer Navigation (TrueNTH-PN), an evidence-based digital peer navigation program for men with prostate cancer and online peer navigator training course. The goal of this project is to adapt TrueNTH-PN for AYA and evaluate its feasibility to overcome barriers to care and support, and enhance patient activation among AYA during the challenging post-treatment phase. In partnership with AYA cancer survivors, the Canadian Cancer Society, Young Adult Cancer Canada, a digital app design firm and technology provider, our cross-Canada team will: (1) Adapt and evaluate the usability of the TrueNTH-PN app for AYA; (2) Adapt and evaluate the effectiveness of the Peer Navigator Training Course for AYA; and (3) Determine the feasibility, acceptability and preliminary effectiveness of the new AYA-PN program among post-treatment AYA cancer survivors. This project will produce an innovative solution to an important service gap in the lives of AYA with cancer. It has the potential to address the support needs of AYA, overcome barriers to care, and empower AYA to take proactive role in managing their health. In addition, it will give rise to AYA peer navigators with specialized skills, which could fill gaps in disrupted education and career paths, and help to attain future goals.