The contentious relationship between corporate social responsibility (CSR) and corporate financial performance (CFP) has been extensively and yet inconclusively debated in the sustainability literature. We further investigate the link between CSR and CFP by examining the mediating role of green innovation performance (GIP). We perform pooled ordinary least squares (OLS) analysis on a panel data of UK firms from 2006 to 2017 provided by the ASSET4 database. We find that CSR is positively and significantly associated with CFP and that GIP plays a significant and positive mediating role in this relationship. Our findings contribute to the extant sustainability literature by using a comprehensive measure of CFP and addressing the mediating effects of GIP on the link between CSR and CFP. The results provide policy, practice, and research implications as investors demand more robust CSR information, regulators establish environmental and climate change rules, and companies focus on the efficiency and effectiveness of their green innovation practices and performance.