Despite the exponential growth of collaborative consumption practices, online fashion renting, an important type of collaborative fashion consumption, is still underexplored. Drawing on the theories of Reasoned Action (TRA) and Innovation Diffusion, we developed a holistic research framework to explore the motives for online fashion renting. By analyzing a total of 300 usable responses collected by a research market company using structure equation modeling (SEM), we found that attitudes and subjective norms positively influenced consumers’ intentions to engage with online fashion rental services. Moreover, we found that environmental awareness also had a significant influence on attitudes toward fashion renting through online platforms, and that relative advantage, amplified by personal innovativeness and fashion consciousness, also positively influenced consumers’ attitudes toward online fashion renting. Interestingly, price consciousness did not contribute to relative advantage.