This research aims to explore the effect of good corporate governance on the performance of listed companies in Saudi Arabia. In particular, the research focuses on the effect of effective internal audit and ERP on corporate governance and, subsequently, firm performance. A questionnaire was used to collect the data. The results indicated that effective corporate governance could be attained by having a good internal audit and ERP system. The results conclude that proper corporate governance positively affects firm performance, and effective internal audit activities and successful ERP implementation enhance corporate governance, eventually leading to better performance. The findings of this study are beneficial to Saudi listed companies and other GCC and their policymakers since social, political, and economic contexts are similar. Even though the study's findings provide extensive evidence regarding corporate governance and firm performance, this study has its limitation as respondents represented a small sample of listed companies and cannot be generalized to all listed companies.