Caregivers and siblings of youth with mental illness often experience role-related psychological challenges, and it is important to focus on the needs of these family members. Existing literature demonstrates that caregivers and affected children benefit from participation in peer support and family-centered programs. This paper describes the Sibling Support Program: A Family-Centered Mental Health Initiative (SSP), a novel intervention for families of youth with mental illness. The SSP distinguishes itself from existing family-centered programs in that it utilizes a unique combination of peer support, parent mentor guidance, and clinician-led group therapy. The paper details the structure of the treatment model and presents preliminary data from participant surveys. Results show preliminary indications that the program provides both emotional and practical benefits. Along with high satisfaction ratings, family members report decreased feelings of isolation, gains in knowledge, and more positive thinking after program participation. Caregivers report that the SSP helped improve their understanding about the impact of a child's mental illness on family members, and that they learned about effective family management strategies and access to resources. Siblings report learning coping strategies and feeling better after meeting peers with shared experiences.