The endured efforts by multilateral and regulatory bodies in entrenching global corporate best practices have been put in doubts by the incessant high-profile corporate failures around the world. This paper is an attempt to contribute to the corporate governance-performance debate. It employed Generalized Method of Moments (GMM) on a panel sample of 8 out of a total of 12 oil and gas firms listed on the Nigerian Stock Exchange for the period, 2004 through 2022 to examine empirical relationships among corporate governance, ownership mechanisms and performance. The results provide evidence of positive relationship between proportion of shares held by institutions and return on equity. Consistent with earlier empirical evidences and the views that foreign shareholding brings foreign capital and managerial expertise and thus enhance performance, this study found significant positive influence of foreign ownership on both return on equity and share price. The findings also argued in favour of the positive role of board size, positing that large board size enables a range of knowledge and expertise to help add value by bringing new ideas and different perspectives to the table. Furthermore, the results demonstrated evidence of negative influences of board composition and gender diversity on both share price and net profit margin. Our findings further provide evidence of significant negative effect of leverage on ROE in that highly levered oil and gas firms were associated with lower return on shareholders’ funds. Overall, our results advocate increasing shares owned by institutions and foreign firms, board size and minimizing the appointment of nonexecutive and women directors in order to maximise performance.