To consider the festival's potential as an activist tactic may seem naïve and disconnected from the colonising practices of event tourism. However, today's immersive and curated festival experiences are indebted to a wider festival imagination: a spatial imagination suffused with reversal and transgression. In this paper, we aim to trace a transgressive festival imagination through four vectors of reversal that have contributed to how we imagine both festivals and activism: the crowd, play, appropriation and spontaneity. Each of these point to the significance of a certain kind of festival space, one that is mutable, protean, volatile and transitional, extending both a techne of resistance and operable elements of the creative industries' somatic economy. By tracing the transgressive festival imagination, across festivals and activist practices, we argue that the contemporary urban festival and the performative tactics of social movements share visions of contingency, playful performance and an aesthetic-political heightened energy.