The research study examines three forms of online co-creation: co-creation of socially sustainable activities, co-creation through user-generated content (UGC), and co-creation through electronic word-of-mouth (e-WoM). Initially, the study investigates whether and how each form influences the well-being of Generation Z consumers in Greece. Well-being is dissected into eudemonic (focused on meaning and self-realization) and hedonic (centered on pleasure and comfort) dimensions, as these encompass different emotional and perceptual experiences. Subsequently, the study examines how these well-being outcomes shape the intention to purchase sustainable fashion items.