While immediate emission cuts are more urgent than ever, we witness climate action being hampered by societal opposition and ethical complexities connected to questions of legitimacy, fairness and participation. Securing support for climate action is needed at all levels of decision-making, ranging from institutionalized, democratic processes to households and individuals, their lifestyles and consumption choices. This Special Section advances our understanding of the acceptability and legitimacy of climate policy processes. Its seven articles examine the diverse factors and mechanisms that influence acceptability throughout policy actions and measures. The collection addresses public acceptability, perceived justice, and inclusive participation across policy levels utilizing various perspectives and methods. Empirical findings are anchored in key mitigation sectors, including transportation and mobility, and housing. While the cases predominantly draw on Finland, their insights are broadly relevant and transferable, as Finland shares many climate policy challenges with other regions.