This study examines how the government's participation in the product market as a customer affects supplier firms’ environmental, social, and governance (ESG) practices. Using a sample of Chinese listed firms from 2010 to 2020, we find that firms with major government customers exhibit higher ESG performance than those without them. Further analysis shows that female managers, institutional ownership, media coverage, and public attention enhance the positive relationship between major government customers and ESG performance. Overall, the findings suggest that as an important public policy, government procurement can significantly affect stakeholders’ value by improving supplier firms’ ESG performance.