Centring on key state functions of protection and the promotion of the economic and social well-being of its citizens, the welfare state describes a range of functions related to state intervention aimed at reducing the risk of market failure, ensuring a decent living standard and a certain degree of equality and intergenerational distribution. The welfare state thus often plays a central role in relation to essential issues of people’s daily lives such as housing, employment, income security, health and education. Nevertheless, despite some initial explorations of the relevance of perspectives grounded in sustainability transitions for understanding processes of change and innovation in welfare states, the question of welfare remains a neglected area in transition studies and, until recently, in environmental studies more broadly. Yet the welfare state can both be used to enable and hardwire social protection into transitions to protect ‘stranded workers’ and also have a key role to play, and be heavily impacted by, the social costs and adjustments brought about by the disruptions and dislocations that transitions inevitably bring in their wake. The chapter concludes with a discussion of what ‘sustainable welfare’ might look like as part of a transformation of the welfare state.