Policy Briefing Three: ‘Models of good practice for work with young fathers: the Grimsby Dads Collective case study’, discusses the value of cocreation methodology for implementing and evaluating new social interventions with, and for, young fathers and professionals with a focus on the Young Dads Collective. This briefing illustrates the value of collaborative knowledge generation between researchers, professionals, and communities/citizens for the purposes of service development. The ‘Young Dads Collective North’ and ‘Grimsby Dads Collective’ case studies are examples of “dynamic, locally adaptive community-academic partnerships” (Greenhalgh et al. 2016: 392), that are driving social change and impact through the promotion of father-inclusive practice and policy at local, regional and national levels.