This study explores the critical role of intellectual capital (IC) in ensuring the sustainable performance and growth of European hospitality firms, both large and small, during the unprecedented COVID-19 crisis. Based on an extensive analysis of data from 42,516 accommodation, food, and travel sector firms operating in 18 EU countries during 2012–2021, this research provides crucial insights into the differential impacts of human, structural, and relational IC on profitability and asset growth. The results show that human IC positively affects SMEs’ profitability, while relational IC benefits both small and large firms. On the other hand, structural IC negatively impacted asset growth for both SMEs and large firms before the crisis but had no impact during the crisis. This study offers crucial insights for policymakers, investors, and business leaders alike, emphasizing the importance of investing in human and relational IC as key drivers of sustainable growth and profitability in the hospitality industry. The findings of this study will help firms better navigate the challenges and uncertainties of crises, such as COVID-19, ensuring their long-term viability and success.