Innovation may provide a means for tackling challenges facing childrens social care, some of them deep-rooted and many exacerbated by COVID-19. Welsh Government has recently committed to a significant 3-year investment to support innovation in adults and childrens social care. The delivery of social care in Wales has a complex and multi-faceted approach, involving collaborative working between a range of organisations, which will likely affect decisions around implementation and scale-up of new and/or existing interventions. The aim of the review was to identify any factors (barriers and enablers) that affect the implementation and scale up of an innovation in childrens social care organisations. Ten studies were identified, comprising three secondary studies (reviews) and seven primary studies. Factors potentially influencing scale and spread of innovation were extracted and categorised. The domains (and sub-domains) covered by included studies were; adopters (staff role/identity; carer input), organisation (capacity to innovate; readiness for change; nature of adoption/funding; extent of change needed; work needed to implement), and wider system (political/policy; regulatory/legal; professional; socio-cultural). Enablers for which a clear consensus seems to be emerging across the literature included: specific training and support for professional staff, support and mutual respect within inter-professional and professional-carer relationships, senior management/leadership buy-in and support, multi-disciplinary communication and joint working, and developing compatible data systems to support joint working/collaboration. Barriers for which a clear consensus seems to be emerging across the literature were: short term or lack of funding (the need for funding was presented as an enabler in some studies), and implementation difficulties (e.g. multiple priorities and changing structures). Policy Implications: This review highlights the complexity of the social care models but provides some clear pointers for policy and practice. The findings indicate the need for: senior management buy-in and support, short and longer term funding, multi-disciplinary communication and joint working, good professional (and professional-carer) relationships with support and mutual respect, and specific training and support for professional staff. The confidence in the evidence is uncertain as the study designs included non-systematic reviews and service evaluations; most studies did not use a formal methodology and all had some quality limitations.