This study investigated the impact of money market instruments on the liquidity of listed commercial banks in Nigeria. Time series data were obtained from the Central Bank of Nigeria Statistical Bulletin and publications of the Nigeria Bureau of Statistics, while cross-sectional data were collected from the financial statements of the listed banks. The liquidity of these banks was analyzed as a function of treasury bills, commercial papers, bankers’ acceptances, treasury certificates, and certificates of deposit. Statistical measures including R-squared, probability coefficients, t-statistics, Durbin-Watson statistics, and F-statistics were employed to determine how money market instruments influence bank liquidity. The results indicate that treasury bills contributed 0.08% to the liquidity of commercial banks during the study period, while treasury certificates and bankers’ acceptances added 0.01% and 0.15%, respectively. Conversely, commercial papers and eligible development stocks reduced liquidity by 0.01% each over the same period. These positive contributions align with the study’s a-priori expectations and reflect the effects of financial market reforms. Analysis of cross-sectional bank performance revealed that Access Bank, Ecobank, First City Monument Bank, Unity Bank, and Wema Bank exhibited positive effects, whereas the remaining eight banks recorded negative effects, which may be attributed to differences in management quality and operational environments. Overall, the study concludes that money market instruments account for a moderate portion of variations in commercial bank liquidity over the period examined. The study recommends policy measures such as deregulation to strengthen Nigeria’s money market, reforms to the Central Bank discount window, the introduction of flexible instruments tailored to the needs of banks and investors, and the strategic use of treasury bills to manage commercial bank liquidity effectively.