This paper aims to analyze the external and internal drivers of young consumers’ intention to participate in the sharing economy in tourism. From previous findings, a causal model (PLS) is designed to generate an integrated, practical, and novel structural model that significantly predicts the intention to participate. The model, consisting of nine dimensions, includes consumers’ external and internal variables. Separately, these variables have all been considered relevant in the literature, though they have not been studied jointly before. The descriptive results show the excellent attitude and predisposition of young people toward the tourism sharing economy, which facilitates their participation. Through the model, the importance of all internal and external consumer variables in the formation of intention are proven; however, attitude and social norm are most notable among them. Trust is also a critical variable that serves as the link between internal and external variables. The study provides managers of sharing economy platforms with knowledge to encourage young consumers’ participation in a communication and market orientation context. The generational approach (Generation Z) used also allows the conclusions and implications to be transferred to other regions and sectors.