The machinic city investigates the role of performance art to help us reflect on contemporary urban living, as human and machine agency become increasingly intermingled and digital media is overlaid onto the urban fabric. This is illustrated by several case studies on performance art interventions from artists such as Blast Theory, Rafael Lozano-Hemmer and Rimini Protokoll, which draw from a rich history of avant-garde art movements to create spaces for deliberation and reflection on urban life and to speculate on its future. As cities are increasingly controlled by autonomous processes mediated by technical machines, the performative potential of the aesthetic machine is analysed, as it assembles with media, Capitalist, human and urban machines. The aesthetic machine of performance art in urban space is analysed through its different – design, city and technology actants. This unveils the unpredictable nature and emerging potential of performance art as it unfolds in the machinic city, which consists of assemblages of efficient and not-so-efficient machines. The machinic city pays particular attention to participation, describing how digitally mediated performance art interventions in urban space foreground different modes of subjectivity emerging from human and machine hybrids. This highlights the importance of dissensus as a constitutive factor of urban life and as a means of countering machinist determinism in present and future conceptualisations of city life.