One of the fundamental questions in strategic sustainability communication is how to foster sustainable transformation utilizing purposeful communication. As stakeholders act in the context of their own perceptions of the capability and effectiveness of corporations to tackle the climate crisis, it is vital to approach strategic communication from a perceptual perspective in addition to functional, managerial, and others. This theoretical contribution proposes “corporate environmental efficacy” as a set of beliefs of the capability (corporate self-efficacy, corporate efficacy, and corporate responsiveness efficacy) and effectiveness (corporate response efficacy) of corporate environmental action. Standing on firm interdisciplinary legs, we propose an integrative framework to understand stakeholders’ confidence in sustainable transformation. Key takeaways include a nuanced understanding and operationalization of corporate environmental efficacy, as well as a communication strategy for corporate efficacy. We suggest that further development of an empirical corporate environmental efficacy construct may offer scholars and, not least, practitioners a stakeholder-centric framework to constitute, organize, and evaluate strategic communication for sustainability. In doing so, corporations can effectively engage with stakeholders and reciprocally drive sustainable transformation—moving beyond strategic communication of sustainability to acknowledge that corporate environmental efficacy has the potential to initiate a new cycle of stakeholder-driven and, therefore, more resonating communication.