The main objective of this study is to explore the dynamic relationship between the level of democracy and the amount of fossil fuel in the energy consumption mix in Nigeria over the period 1975–2020. To achieve this objective, the autoregressive distributed lag (ARDL) bounds testing method is applied. The results revealed that democracy has a positive and significant long (lasting) and short run (immediate) effects on the amount of fossil fuel in the energy consumption mix in Nigeria. However, the positive effect decreases significantly with an increase in the level of oil dependence in the short run. The results of this study in general support the view that high dependence of political democratic institution on oil wealth reduces the positive effects of democracy in making public goods available in oil-exporting economies. This study therefore recommend that diversification away from fossil fuel in energy consumption mix in Nigeria which may require formulating appropriate policies that will increase access to cleaner forms of energy (e.g. solar and wind energy) in the economy.