Alongside formal agencies and specialist services, informal and social networks play a pivotal role in responding to domestic abuse in the community. Friends, relatives, and neighbours are uniquely placed to recognise domestic abuse, respond to victim-survivors, and refer to wider services. Yet, informal networks may not know how to respond and feel overwhelmed or ill-equipped to offer support. This mixed method systematic review examined the role of training for equipping and enabling informal supporters to respond to disclosures of abuse. To do so, four bibliographic databases, alongside specialist repositories and websites, were searched for empirical studies of educational programmes tailored towards informal networks. Nine included studies were subject to data extraction and quality appraisal by two members of the review team. A thematic synthesis of qualitative data was undertaken to identify the characteristics of training deemed important by informal supporters. The findings focused on engaging informal supporters in the issue of domestic abuse, training content, materials, and delivery. The themes were translated into ten recommendations and juxtaposed with studies reporting quantitative evidence of effectiveness. The resulting matrix was used to identify five characteristics of successful training for informal supporters. These included training content that covered (a) warning signs and nature of domestic abuse, (b) impacts of abuse, and (c) how to respond/local resources. Tailoring training to the context/audience and the use of nontext formats were also evidenced by included studies. The review highlights the potential of educational programmes for enabling community responses to victim-survivors. Such interventions offer opportunities for formal agencies to collaborate with informal networks and strengthen the societal-wide response to domestic abuse.