Transmedia storytelling (TS) narrates and supplements a storyworld in a unified and coordinated manner across multiple media channels and forms. It overcomes the limitations of traditional media’s singularity and restricted reach by leveraging digital technologies. Advancing digital technologies have introduced diverse media into fashion exhibitions, supplementing interpretation and expanding the storyworld to aid the understanding of fashion’s social, cultural, and artistic meanings. This study aims to examine the effectiveness of social media in facilitating TS within fashion exhibitions. In researching this topic, we studied the concepts and applications of TS and social media in fashion exhibitions, using a 2023 fashion week organised by a South Korean universityas a case study. Purposeful sampling involved interviews and questionnaires with exhibition committee members, participants, and visitors. Reflective thematic analysis (RTA) was employed to iteratively analysis the data. This study clarifies the unique functions of various media forms and channels in TS for fashion group exhibitions, with a focus on their synergistic effects. Reflective thematic analysis of the results indicate that TS effectively addresses the challenges of narrating complex and fragmented exhibitions by attracting visitors, supplementing content gaps, and expanding engagement. The collected data offers empirical evidence of TS’s potential in emerging exhibition storytelling and highlights Instagram’s key function within a TS system.