The goal of this paper is to examine to what extent R&D investment and stock market development promote clean-energy consumption and environmental protection across a panel of 30 OECD economies. Based on the theoretical approach, study employs robust panel econometric models, which account for cross-sectional dependence in the analysis and uses annual data, spanning the period 1996–2013. The empirical results illustrate that R&D and stock market have a significant long-run equilibrium relationship with clean energy and CO 2 emissions. The long-run elasticities display that R&D and stock market growth have a significant positive impact on clean-energy consumption, while they have a negative effect on the growth of CO 2 emissions....