This study examines the impact of monetary policy on economic growth in Nigeria over the period 1980 to 2024. Despite sustained policy interventions by the Central Bank of Nigeria, economic growth has remained unstable, characterized by periods of expansion and contraction. This study investigates the extent to which key monetary policy instruments—money supply, interest rate, inflation, and exchange rate—affect output growth proxied by GDP. Using annual time-series data sourced from the World Development Indicators and the Central Bank of Nigeria, the study employs econometric techniques to analyze both short-run and long-run relationships. The findings reveal that money supply and exchange rate exert significant influence on economic growth, while interest rate effects are relatively weak. The results further show that Nigeria’s growth trajectory is highly volatile and sensitive to external shocks. The study concludes that while monetary policy plays a critical role in influencing economic performance, its effectiveness is constrained by structural weaknesses such as inflation instability, exchange rate volatility, and overdependence on oil revenue. JEL Classification: E52, E31, O47