This study aims to determine the Impact of Board Structure on the Performance of listed Commercial Banks on the Colombo Stock Exchange. This study examines the relationship between Board Structure and Corporate Financial Performance of listed commercial banks using a sample of 12 banks listed on the Colombo Stock Exchange, based on data from 2015 to 2019. Descriptive, correlation and regression analyses were performed to achieve the study objectives. This study uses the company's performance based on the following financial performance measures: return on assets (ROA) and return on equity (ROE) and board structure consisting of board size, female board members, non-executive directors, and frequency of board meetings. Bank capital is used as the control variable in this study. The study's findings suggest that the frequency of board meetings and non-executive directors have a negative and substantial influence on ROE, while the frequency of board meetings has a significant and negative impact on ROA. Additionally, bank capital has a positive and significant impact on ROA. However, the board size, female board members, and bank capital have no significant impact on ROE while board size, non-executive directors, and female board members have no significant impact on ROA of CSE-listed commercial banks. This study contributes to the literature on corporate governance and firm performance by providing the framework that affects the relationship between board structure and firm performance in the context of listed commercial banks. The findings of the study are important for policymakers, investors, regulators, and other bankers of the country. Commercial banks listed in Colombo Stock Exchange would put more attention on the structure and quality of the board to improve their performance. Concerning the study's scope, the present study only included CSE-listed commercial banks. Thus, additional research is needed to study the entire Sri Lankan banking system and 20 business sectors. Further, this study only looked at accounting-based measures such as ROA and ROE. Tobin's Q, for example, can be employed as a dependent variable. Future studies should be done by including cross-border analysis of developing and developed countries.