This study investigates the effect of audit committee characteristics on the financial performance of listed oil and gas companies in Nigeria over the period 2014 to 2024. The study examines explicitly four key audit committee attributes: size, independence, frequency of meetings, and gender diversity. Return on Assets (ROA) was adopted as the proxy for financial performance, and secondary data were sourced from the annual reports of nine oil and gas firms listed on the Nigerian Exchange Group. The data were analysed using panel least squares regression under a random effects framework, following a Hausman test that confirmed the suitability of the random effects model. The unit root test confirmed that all variables were stationary at the level, ensuring the robustness of the regression results. Findings from the study revealed that all audit committee characteristics— size, independence, meeting frequency, and gender diversity—had a positive and statistically significant influence on ROA. These results underscore the critical role of audit committees as effective governance mechanisms that enhance transparency, accountability, and firm profitability. The study aligns with agency theory, which posits that structured oversight mechanisms reduce agency conflicts and protect shareholders’ interests. Based on the findings, the study recommends that regulatory agencies enforce best practices on audit committee composition, promote independence and diversity, and encourage firms to institutionalise frequent committee meetings. These measures will strengthen governance structures and foster improved financial outcomes in Nigeria’s oil and gas sector