The main aim of this study is to investigate the influence of institutional investors’ ownership (INOW) on firms’ environmental, social, and governance (ESG) reporting in Saudi Arabia. Using data on ESG reporting from the Bloomberg database for 206 Saudi-listed firms spanning the period from 2010 to 2019 and employing ordinary least squares regression (OLS), the results show a significant and positive association between INOW and ESG reporting. When institutional investors are classified into government and privately managed institutions, the research findings clearly show that only government-managed institutional investors (Govt_IO) are linked to ESG reporting in a positive and significant way, whereas there is no significant association between privately managed institutions (Prvt_IO) and ESG reporting. In addition, when the ESG score is disaggregated by individual pillars, we find Govt_IO is positively associated with environmental score and social score. These results suggest that the association between INOW and ESG varies depending on the types of INOW, as well as the ESG components. Even after several additional analyses, including tests for endogeneity, the main results of this study still hold.