Improving energy efficiency is crucial for China’s transition to high-quality development. While prior research has examined the macro-level factors, the role of CEOs in improving energy efficiency has yet to be explored and empirically tested. Drawing on the Upper Echelons Theory, this study investigates how CEO industry expertise, defined as prior experience or specialization in the firm’s core industry, affects corporate energy efficiency. Using a panel dataset of A-share listed firms in heavily polluting and new energy industries in China, multiple regression models are employed to test the relationship, along with mediation analysis to examine the role of green innovation and subsample analysis to explore contextual variation. We find that CEO industry expertise significantly enhances energy efficiency, with green innovation serving as a key mechanism. Moreover, the effect is more pronounced in non-state-owned firms and under high media attention. These findings highlight the importance of executive characteristics in shaping energy performance, contribute to the literature by providing a micro-level perspective on the determinants of energy efficiency in the Chinese context, and offer valuable implications for CEO selection, corporate sustainability practices, and green governance.