Based on neo‐institutional theory, this paper examines whether social trust can influence corporate social responsibility (CSR). Using a sample of 4,209 observations selected from 788 firms listed in China between 2008 and 2015 and adopting an ordinary least square regression, we provide strong empirical evidence showing that social trust is positively associated with CSR. The result supports the view that social trust, as a kind of socially normative force, helps corporate managers safeguard stakeholders' interests by engaging in socially responsible activities. Our result holds after applying a series of robustness tests. We further find the positive relationship between social trust and CSR is more pronounced for state‐owned companies. This paper is one of the first to focus on and examine the relationship between social trust and CSR, and the findings contribute to our understanding of the determinants of CSR and highlight the influential role of social trust in improving CSR.