The study examined the relationship between ownership structure and financial performance of commercial banks in Kenya for the period 2009-2020. The data were collected from audited financial statements of 39 commercial banks in Kenya. Regression results found strong evidence on ownership structures in explaining the differences in commercial banks' financial performance. The results established that the greatest influence of ownership structures was on net interest margin at 53.04% and return on assets at 31.37%. Influence of ownership structures was found to be low on return on equity at 3.32% and earnings per share at 2.13%. The results found a negative association between state ownership and net interest margin, negative association between management ownership and both net interest margin and earnings per share, negative association between institutional ownership and return on assets and a negative association between foreign ownership and earnings per share. Based on the findings, commercial banks should vary their ownership structures to boost financial performance. Secondly, banks with high percentage of state ownership should consider partial privatization to improve corporate governance practices. Third, banks should adopt managerial ownership policy limiting the proportion of equity stock on executives to limit their powers in strategic decision making. Fourth, the study proposes a percentage limit on equity stock of an individual institutional investor. Lastly, the study proposes that bank's management to come up with a policy detailing the role and place of foreign investors in strategic decision making to ensure their presence in every decision undertaken by bank managers.