This study assesses the economic impact of Smart Tourism Platform (STP) projects in Seoul. We begin by outlining the architecture of STP, which comprises seven distinct layers, to deepen our understanding. Next, we analyze their economic effects using a four-step approach that includes Delphi surveys and the updating of Seoul’s 2015 national input-output table to a 2021 regional version through RAS and location quotient (LQ) techniques. Our findings indicate that a 2.9 billion KRW investment in STP projects creates about 3.8 billion KRW in production effects across Seoul’s industries, which is expected to generate income effects of 1.7 billion KRW, value-added effects of 2.4 billion KRW, and jobs for around 55 individuals. The insights gained from this research aim to further the understanding of STPs, providing valuable guidance for policymakers and industry stakeholders.