Abstract Purpose This study examines the relationship between corporate governance mechanisms and the financial performance of listed financial services firms in Nigeria. Design/methodology/approach The study uses a purposive sampling technique to select 34 companies out of 47 financial companies on NSE and employs panel regression method to obtain the numerical estimates of the coefficients in the model using STATA. Findings The findings of this study reveal a significant positive effect of board size (BS) on earnings per share (EPS) of listed financial services firms in Nigeria. Additionally, the study found a negative insignificant relationship between BC with EPS. In the same vain, the study also identifies an adverse effect of the audit committee size (ACS) on EPS of listed financial services firms in Nigeria. Therefore, the study recommends that policies and practices be aligned with global governance practices, as this will bolster investor confidence, strengthen market competitiveness, and facilitate sustainable development in the Nigerian financial sector. Originality This study contributes a unique perspective to the literature by examining the specific effect of BS, BC, and ACS on financial performance in the Nigerian financial services sector, using current data and robust panel regression analysis. KEYWORDS: Corporate Governance, Financial Performance, Board size, Board Composition, Board Audit Committee Size.