The tourism industry has grappled with the challenges posed by the onset of the coronavirus disease (COVID-19) since the start of 2020, experiencing a complete lockdown that profoundly affected travel activities. This viral outbreak had a critical impact on both the financial and non-financial aspects of life, including the intellectual capital (IC) of the tourism and hospitality sectors. However, there is a scarcity of studies addressing this issue within the context of tourism-related businesses. Thus, this paper aims to investigate the changes in the overall IC and its components before and during the COVID-19 pandemic, with a specific focus on understanding the transformation of IC in the tourism industry of Thailand, a country that is highly dependent on tourism. The study involved 37 tourism-related companies listed on the Stock Exchange of Thailand (SET). Organizational data from financial and annual reports published between 2019 and 2020 were collected for analysis. The assessment of value added intellectual capital (VAICTM) was employed to evaluate the performance of the overall IC and its components during the pandemic. The results, based on the testing of four hypotheses, indicated that most hypotheses were accepted, signifying a substantial transformation in the overall IC performance of tourism-related companies during the pandemic crisis. This transformation was observed in the IC components of physical and human capitals. However, the structural capital was the only IC component that did not experience a significant impact from COVID-19. To comprehend the reasons and effects of the IC transformations during the pandemic, this study delved into the relevant literature. Additionally, the paper includes implications to support firms in preparing for future challenges.