Energy project communication is a crucial task and prerequisite for the success of energy projects, as it contributes to building legitimacy for these projects. In this chapter, we define energy project communication of corporations as a specific subfield of strategic sustainability communication. Based on a literature review, we discuss its characteristics, including communicators, stakeholders, objectives (specifically legitimacy), and implementation. We address the concept of legitimacy as a key objective of strategic energy project communication and discuss how strategic energy project communication attempts to achieve this key objective. We analyze how different types of legitimacy are addressed and which discursive legitimation strategies are of particular importance in this regard. By including literature on both strategic energy communication and legitimation communication, particularly from public relations research and related fields, our chapter brings together two strands of research that have rarely been considered together and provides theoretical implications and impetus for both strands. Our findings also have practical implications as they help communication practitioners to reflect on their communication about energy projects.