Caregivers are increasingly recognized as the backbone of healthcare systems, providing much of community-based chronic disease and long-term care – a demand that will continue to rise as populations age. In response limitations in healthcare and social care institutions, online peer-based caregiver support systems have emerged enabling caregivers to share information, skill development, emotional support, and even caregiving duties. This rapid review characterizes the landscape of peer support for caregivers and identifies the key features and approaches that may be most effective in optimizing these initiatives.