This paper investigates the impact of domestic refining capacity on fuel import dependency in Nigeria over the period 1990–2025. Installed Refining Capacity, Refining Capacity Utilization and Domestic Refining Petroleum Output were used as surrogate for domestic refining capacity while fuel import dependency is the dependent variable. Secondary data were sourced from the National Bureau of Statistics (NBS), Nigeria National Petroleum Company Limited (NNPCL) Nigeria Upstream Petroleum Regulation Commission (NUPRC), and Organization of Petroleum Exporting Countries (OPEC) several issues The Augmented Dickey-Fuller unit root test was employed to examine the stationarity properties of the variables, while the Auto-Regressive Distributed Lag model was utilized to estimate both short-run and long-run dynamics. The bounds testing approach confirms the existence of a long-run relationship among the variables. Empirical findings reveal that installed refining capacity and domestic refining petroleum output had a negative but significant relationship with fuel import output. However, refining capacity utilization exact a positive and significant relationship with fuel import dependency. It was concluded that domestic refining capacity had a substantial impact on fuel import dependency in Nigeria. It was recommended that the Federal Ministry of Petroleum Resources should expand and modernize Nigeria’s installed refining capacity to reduce fuel import dependency.