The idea that the world needs to transition to a more sustainable future is omnipresent in environmental politics and policy today. Focusing on the energy transition as a solution to the ecological crisis represents a shift in environmental political thought and action. This Element employs a political theory approach and draws on empirical developments to explore this shift by probing the temporal, affective, and technological dimensions of transition politics. Mobilising the framework of ecopolitical imaginaries, it maps five transition imaginaries and sketches a counter-hegemonic, decolonial transition that integrates decolonial approaches to knowledge and technology. Transition Imaginaries offers a nuanced exploration of the ways in which transition politics unfolds, and a novel argument on the importance of attending to the coloniality of transition politics. A transition to just sustainable futures requires the mobilisation of post-extractivist visions, knowledges, and technologies. This title is also available as Open Access on Cambridge Core.