Abstract Purpose Intimate partner violence and abuse (IPVA) is a major public health issue with long-term negative impacts on abused adults and affected children. Addressing this complex problem requires a multi-agency response, but barriers to effective joint working remain. This review aimed to understand the factors that influence multi-agency response to families who experience IPVA and to their children. Method We undertook a qualitative systematic review of international literature via five electronic databases and supplemented the review by citation searches, online searches of grey literature, and hand searches of relevant journals. We analyzed data thematically. Results The 31 identified papers reported findings from 29 unique studies undertaken in six countries and drew on data from 1049 professionals across health care, social care, the police, courts, schools and voluntary organisations. The main factors influencing service provider response to IPVA were siloed approaches to IPVA, particularly the separation between adult and childrens services. This influenced assessment and response to risk. Risk was also a consideration when child-protection staff were expected to work with perpetrators in ‘family settings’, even in lower-risk cases. Multi-agency working facilitated information sharing between agencies, an understanding of each other’s remit, and building trust. Conclusion Multi-agency collaboration needs to be supported by clear policies of interaction between agencies. Providers of child protection services, health, mental health, housing police and probation need to be supported by specialist training in IPVA, not only in high-risk cases, but also to relieve pressure on an already overstretched workforce.