The rapidly growing number of people with dementia has created an urgent need for developing socially sustainable care. Sustainability entails the availability of sufficient health and social care services, safety, opportunities for social participation and agency regarding one’s personal life and care services (Littig & Giessler 2005). These principles must apply to persons living with dementia and, at the same time, to the vast number of their informal carers, who play a significant role in providing care. Informal care must not have unfair health, social or economic penalties for unpaid carers (Yeandle et al. 2017). To organise sustainable care, we must engage persons living with dementia and their informal carers in defining it. In this project, a consortium of researchers from the University of Jyväskylä, the Finnish Institute for Health and Welfare and Tampere University (DRNI's first Finnish members, who collaborate with Irish researchers on numerous projects) outline socially sustainable care for persons living with dementia, either in ordinary homes or in care facilities, and their informal carers. Based on qualitative and quantitative data, we examine what it means to live with dementia, what kind of social and institutional barriers and risks of care poverty are faced by persons with dementia and their family carers, and how their participation and agency should best be supported on the level of daily life, social participation and care services. In addition, we contribute to the theoretical research on the social relational model of dementia. Finally, the new model is used as a basis for definitions of socially sustainable dementia care.