AbstractThe study examines the dynamic relationships between sustainable equity investment and economic policy uncertainty of G‐20 countries using monthly environmental, social, and governance (ESG) equity and economic policy uncertainty (EPU) indices. Using the autoregressive distributed lag model and nonlinear autoregressive distributed lag model models, the study finds a negative long‐run relationship between sustainable equity investments and economic policy uncertainties in Australia, Canada, the USA, Brazil, Mexico, Germany, Italy, and Japan. Investors in these G20 countries may perceive that companies with higher ESG performance are more likely to face regulatory scrutiny, legal action, or reputational damage if they are associated with high levels of economic policy uncertainties. As a result, ESG market indices may underperform when EPU is high and vice versa. It supports prospect theory and suggests that individuals are more sensitive to potential losses than gains. On the contrary, the relationship is positive in the case of the USA, Brazil, China, and to some extent India. This might be because firms with high ESG performance could manage risks better and seize opportunities associated with EPU, which helps ESG market indices to outperform when EPU is high. It is supported by the legitimacy theory that says to maintain the legitimacy and credibility of the company, the investment must be invested in ESG initiatives, which can lead to improved long‐term financial performance and market value.