The contribution of intellectual capital (IC) on financial performance have been found in previous studies but whether IC can also be utilised to improve non‐financial performance has been understudied; let alone the contributions in different economic conditions (normal and crisis periods). This study aims to provide empirical findings to answer these issues by defining non‐financial performance in terms of the environmental, social, and governance (ESG) performance and COVID‐19 pandemic to represent the crisis. Non‐financial companies listed on stock exchanges in the Southeast Asia countries that are member of ASEAN (Association of Southeast Asian Nations) were selected as the samples for the research period of 2016–2020. The results show that the IC has a positive association with financial performance but a negative relationship with ESG performance. With the COVID‐19 pandemic as the moderating variable, the results show that the pandemic period is not found to moderate the effect of the IC on financial performance and ESG performance. These results indicate that under normal conditions prior to the economic crisis caused by COVID‐19, companies in Southeast Asia prioritised the use of IC to improve financial performance. Meanwhile, during the COVID‐19 pandemic, companies in the region have not utilised IC to improve their financial and non‐financial performance. The findings that IC affect ESG performance negatively need a serious attention amid the increasing awareness of sustainability and the expected role of corporate in the achievement of the Sustainable Development Goals (SDGs).