There has been a continuous and controversial debate about the relationship between carbon performance, carbon disclosure, and economic performance. This study investigates whether corporate economic performance is influenced by carbon performance and disclosure and whether carbon (media) legitimacy mediates such relationships. This study provides a broader understanding of the relationship between carbon performance, disclosure, and economic performance by investigating the mediating role of carbon (media) legitimacy, and offers further evidence from the UK context. Based on a balanced panel data of 95 UK firms between 2009 and 2014 (amounting to 475 observations in total) and using path analysis, we find that improving the company’s carbon performance is not financed by shareholders, and carbon (media) legitimacy as an intangible asset enhances the economic performance of the firm. We also find that while carbon disclosure does not directly improve economic performance, it indirectly does so via carbon (media) legitimacy. Finally, the results show while carbon performance is not reflected in carbon (media) legitimacy, carbon disclosure as a legitimizing tool strongly enhances carbon (media) legitimacy. Overall, our results suggest that voluntary carbon disclosure, regardless of the firm’s underlying carbon performance, is an effective tool to manage corporate (media) legitimacy, and subsequently improve economic performance. Thus, voluntary carbon disclosure in the UK may hinder future improvements in a firm’s carbon performance.