Financial performance is a rallying point for all stakeholders, be it management, regulators, investors and potential investors. The continuous survival and growth of any business is dependent on its performance and as such the need to look for factors to enhance the continuous performance of firms. It is to this end that the study examines the impact of audit committee characteristics, ownership structure on financial performance of listed Oil and Gas companies in Nigeria over the period of 2010 -2015. The populations consist of nine listed Oil and Gas companies as at 31st December, 2015 while a sample of seven companies were used after eliminating two through criteria. Secondary source of data was used and were obtained through the annual reports and accounts of the selected companies. Panel multiple regression technique was used and Stata 13 was used as tool for data analysis. The result indicates that audit committee composition, audit committee financial expertise, managerial ownership and institutional ownership have significant positive impact on financial performance of listed oil and gas firms in Nigeria. Audit committee size revealed significant negative influence on financial performance of firms. However, the study did not find any significant impact of audit committee meetings on financial performance. The study recommends amongst others that; the members of the audit committee should highly be composed of members with knowledge of finance in order to make them effective which will affect financial performance positively. At least 45% of audit committee members should be financially literate.