This research employs a mixed-methods approach using content analysis and discourse analysis to examine the corporate identity shift of Qatar Petroleum to QatarEnergy in 2021, with a focus on its sustainability communication strategies. The content analysis defines and quantifies trends in the organization’s public messaging about sustainability. This quantitative foundation informs a discourse analysis which involves a qualitative analysis of the company’s evolving stance toward environmental responsibility. The sample consists of public domain messages about the rebranding and sustainability, published and circulated from its announcement in October 2021 to December 2023. This study aims to answer two questions: (1) How much do these communications and initiatives by QatarEnergy represent a real commitment to sustainability? (2) Which are the critical discourses that appear most in QatarEnergy’s communication on the rebranding, especially those on sustainability and environmental responsibility? The results show that QatarEnergy emphasizes renewable energy projects, carbon capture and storage, and international partnerships in its sustainability communication. The discourse analysis reveals key themes such as responsible business conduct, innovation, and collaboration, framing QatarEnergy as a proactive and comprehensive leader in the global energy transition. These findings contribute to a broader discussion on corporate sustainability communication and provide insights for organizations aiming to navigate similar transitions.