Cities can play a pivotal role in accelerating climate action (i.e., climate mitigation and adaption). Yet, the success of cities’ climate strategies strongly depends on the cities’ residents, as city residents often have to accept, adopt, undertake and participate in climate actions. In the current paper, we discuss how better understanding city residents’ motives – and particularly the personal and group values that underlie city residents’ climate actions – could foster climate action in cities. Importantly, we discuss the rich literature in social sciences on personal values, which – though typically overlooked by policy makers – highlights the relevance of focusing on personal biospheric values (i.e., caring about nature and environment) in explaining and promoting individuals’ climate actions. Additionally, we provide novel insights in how perceived biospheric group values (i.e., the extent in which relevant groups are perceived to endorse biospheric values) can strengthen the value-base for climate actions, particularly among those residents who weakly endorse biospheric values themselves. Critically, we provide concrete examples of how cities can strengthen the group value-base for climate actions, thereby showing how cities can play a unique role in engaging residents in climate action.