The Kenyan banking sector has faced significant volatility in recent years, notably marked by a decline in Return on Assets (ROA). This decrease reflects the sector's struggles with rising inflation, currency depreciation, and increased non-performing loans. Economic uncertainties and tighter global monetary policies have compounded these challenges, resulting in a more unstable financial environment. This volatility underscores the sector's sensitivity to both domestic and international economic conditions. In response, this research aimed to investigate the effect of monetary policy instruments on the financial performance of banks in Kenya. The study sought to analyze the effect of lending rates, money supply, open market operations (OMO), and the Central Bank Rate (CBR) on banks' financial performance. Anchored on four relevant theories—the Loanable Funds Theory, Quantity Theory of Money, Keynesian Economics, and Zero Bound Theory. The research utilized a causal design and a multiple linear regression model. Covering all 42 banks operating in Kenya from January 2009 to December 2023, the study employed secondary data. The correlation analysis reveals significant relationships between the monetary policy instruments and the financial performance of commercial banks in Kenya. Lending rates demonstrate a positive relationship with financial performance, suggesting that higher rates may benefit banks’ profitability. In contrast, both money supply and central bank rate show negative associations with financial performance, implying that increases in these variables might hinder profitability. Additionally, the analysis indicates a positive link between open market operations and bank performance, highlighting the varied effects of these monetary instruments on the banks' financial outcomes. Collectively, these insights underscore the interconnectedness of these monetary policy instruments and their impact on the financial performance of banks in Kenya. Given the complex interplay of these factors, policymakers should adopt a holistic view, regularly reviewing and adjusting policies to maintain economic stability while supporting a robust banking sector.