Despite their importance and policies to improve their collection, tax revenues in some economies, especially developing ones, are low compared to the financing needs for economic development and growth. Whereas the literature has identified a wide range of tax revenue mobilisation drivers, this paper stands out from previous contributions by emphasising the role of economic complexity. Using a sample of 122 countries, this paper finds that the more complex an economy is, the more taxes it mobilises. This finding survives several robustness analyses that use an alternative measure of economic complexity, and endogeneity issues resulting from the reverse causality between economic complexity and tax revenue. Our result is supported by the view that economic complexity improves economic development and human capital and reduces income inequality which therefore ameliorates tax collection. In sum, these results call for measures aimed at strengthening diversification through industrialisation and encouraging innovation.