This paper proposes a model of how incumbents and new entrants engage in sustainable entrepreneurship. We suggest that in the early stages of an industry's sustainability transformation, new entrants ('Emerging Davids') are more likely than incumbents to pursue sustainability-related opportunities. Incumbents react to the activities of new entrants by engaging in corporate sustainable entrepreneurship activities. While these 'Greening Goliaths' are often less ambitious in their environmental and social goals, they may have a broader reach due to their established market presence. This paper analyses the interplay between 'Greening Goliaths' and 'Emerging Davids' and theorizes about how it is their compounded impact that promotes the sustainable transformation of industries.