<p>Publicness and spatiality are two fundamental attributes of public space. The advancement of digital technologies and the proliferation of social media platforms have increasingly situated publicness within both physical and virtual spaces simultaneously. This study examines the nature of intertwined physical–virtual public space and establishes an assessment framework for physical–virtual publicness. It investigates the four key dimensions of public space—form, function, management, and meaning—and explores the physical–virtual interaction in each dimension concerning spatiotemporal hybridization, cyborg engagement, digital mediation, and technocapital differentiation. Building on a review of diverse assessment models of publicness, the study proposes a multidimensional set of criteria, encompassing accessibility, affordance, vitality, and inclusiveness, to evaluate the physical–virtual publicness of public space. While acknowledging the potential applications and limitations, this framework reconceptualizes publicness as a multifaceted whole emerging through an ongoing physical–virtual interaction process and provides a robust analytical tool for assessing the hybrid nature of contemporary public space in the digital age.</p>