Social imaginary is a sociological concept referring to the set of values, institutions, laws and symbols through which people imagine their social whole. This article unpacks what might be needed to develop an all-island welfare imaginary. Literature points to the importance of ‘institutional fit’, ‘policy opportunity’ and ‘learning processes’ as factors facilitating policy transfer between different jurisdictions. An absence of ‘institutional fit’ presents barriers to policy transfer, but even where there is institutional fit, effective policy transfer requires sufficient policy opportunity and effective policy learning processes. We find potential for convergence between the Irish and Northern Irish welfare systems in that both are broadly neoliberal in character, with common features and challenges. However, recent reforms created divergence in their direction of travel, as is evidenced in social security responses to the pandemic. Looking to the future, labour market disruption and restructuring is likely as economies and societies cope with impacts of the pandemic, future automation and climate challenges, and possible constitutional changes across the UK. Negotiating these new social risks will require greater agility and navigational agency of citizens. Enabling institutions will be key, as will maximum social and economic participation and cohesion; these policy goals offer compass points to guide mutual travel for working age welfare and social security policy, north and south. This article promotes knowledge mobilisation towards an ‘island welfare imaginary’ that draws on Nordic social democratic and universal models of welfare states and seeks to maximise social and economic participation as a way of rooting solidarity and reciprocal citizenship.