The issue of sustainability has become a critical and very important issue to be discussed because of the increase in environmental damage, unethical corporate behaviour, exploitation of child labour and other economic, social and environmental challenges. Companies that implement sustainability practices publish their sustainability activities in sustainability reports, considered an integral part of the communication process between business enterprises and various stakeholders. The activities are summarised in a separate sustainability report, which is then audited before being presented to stakeholders. This study aims to examine the effect of sustainability disclosure on firm performance, as well as to examine the effect of CEO Power as a moderator between the relationship between sustainability disclosure and company performance. Sustainability disclosure is measured using the GRI index, CEO Power is measured by the number of years of experience as CEO, and accounting performance is measured by ROA, while market performance is measured by Tobin's Q. This study uses panel data analysis with Generalised Least Square (GLS) technique with a sample of primary and secondary sector companies listed on the Indonesia Stock Exchange (IDX) in the observation period 2014-2020. The results show that sustainability disclosure has a significant effect on company performance, both accounting-based and market-based performance. However, the presence of CEOs with work experience as CEOs in previous companies cannot have a significant effect on the relationship between sustainability disclosure and firm performance. These results have implications for strengthening the focus of companies to start presenting more comprehensive non-financial information such as sustainability reports that have an impact on improving company performance, especially market performance.