This entry examines postdigital citizen research using the figure of the postdigital citizen researcher. Postdigital citizen research involves both doing and reflecting—a practice of reflection-upon-action that draws from critical pedagogical traditions undergirding postdigital scholarship. Postdigital citizen researchers are much more than data providers for predetermined research questions; they are co-creators of knowledge who critically examine the research process itself. Postdigital citizen researchers occupy diverse and often contradictory possibilities in relation to knowledge production, technological systems, and institutional power. Postdigital citizen researchers are simultaneously empowered and exploited, insiders and outsiders, humans and machines, willing participant-researchers and unwitting data subjects. Understanding postdigital citizen research requires holding these tensions together, exploring them and interrogating them, rather than resolving them.