The ageing of populations in European welfare states presents economic challenges for the maintenance of current levels of welfare provision in the future. To ensure the well-being of all age groups, alternative approaches to well-being policies and a more comprehensive measurement of well-being are required. We argue that an equal distribution of life satisfaction, especially across age groups and generations, is a key indicator of social sustainability. Furthermore, we demonstrate empirically that higher levels of social trust, gross domestic product (GDP) per capita, and social protection expenditure are associated with higher levels of life satisfaction across European countries and age groups. The associations are particularly strong for the older population.