This study employs a dataset comprising Chinese A-share listed companies from 2012 to 2021, with the objective of empirically examining the relationship between corporate ESG ratings, external media sentiment, and corporate innovation performance. The findings indicate that a favourable ESG rating can significantly enhance a company’s innovation performance, with external media sentiment exerting a supportive influence. Further analysis indicates that the optimistic media sentiment generated by a favourable ESG rating serves to reduce the financing threshold for companies, alleviate external financing constraints, and ultimately promote innovation performance. Heterogeneity analysis shows that in companies with higher financing constraints and lower levels of marketization in their location, the improvement of ESG ratings has a better effect on enhancing innovation performance. By examining the influence of external media sentiment on the relationship between ESG ratings and a company’s innovation performance, this study contributes to the understanding of the mechanisms through which media affects a company’s quality development. These findings have implications for the stimulation of a company’s innovation vitality and the guidance of their accelerated transformation.